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  • The role of computational results databases in accelerating the discovery of catalysts
    Nat. Catal. Pub Date : 2018-10-15
    Carles Bo, Feliu Maseras, Núria López

    The role of computational results databases in accelerating the discovery of catalystsThe role of computational results databases in accelerating the discovery of catalysts, Published online: 15 October 2018; doi:10.1038/s41929-018-0176-4Databases of computational results hold high promise for accelerating catalysis research. Still, many challenges remain and consensus on facets such as metadata, reliability and curation is crucial to transform the hype into an attractive technology.

    更新日期:2018-10-16
  • Water oxidation on a mononuclear manganese heterogeneous catalyst
    Nat. Catal. Pub Date : 2018-10-15
    Jingqi Guan, Zhiyao Duan, Fuxiang Zhang, Shelly D. Kelly, Rui Si, Michel Dupuis, Qinge Huang, John Qianjun Chen, Chunhua Tang, Can Li

    Water oxidation is the prerequisite for dioxygen evolution in natural or artificial photosynthesis. Although it has been demonstrated that multinuclear active sites are commonly necessary for water oxidation, as inspired by the natural oxygen-evolving centre CaMn4O5, a multinuclear manganese cluster, whether mononuclear manganese can also efficiently catalyse water oxidation has been a long-standing question. Herein, we found that a heterogeneous catalyst with mononuclear manganese embedded in nitrogen-doped graphene (Mn-NG) shows a turnover frequency as high as 214 s−1 for chemical water oxidation and an electrochemical overpotential as low as 337 mV at a current density of 10 mA cm−2. Structural characterization and density functional theory calculations reveal that the high activity of Mn-NG can be attributed to the mononuclear manganese ion coordinated with four nitrogen atoms embedded in the graphene matrix.

    更新日期:2018-10-16
  • Distributed processes for biomass conversion could aid UN Sustainable Development Goals
    Nat. Catal. Pub Date : 2018-10-11
    Daniel E. Resasco, Bin Wang, David Sabatini

    Distributed processes for biomass conversion could aid UN Sustainable Development GoalsDistributed processes for biomass conversion could aid UN Sustainable Development Goals, Published online: 11 October 2018; doi:10.1038/s41929-018-0166-6Catalysis can contribute in many ways to achieving the UN Sustainable Development Goals. Here, the opportunities arising through the interplay of biomass valorization and distributed production approaches are discussed.

    更新日期:2018-10-12
  • Describing perovskite catalysts
    Nat. Catal. Pub Date : 2018-10-11
    Marçal Capdevila-Cortada

    Describing perovskite catalystsDescribing perovskite catalysts, Published online: 11 October 2018; doi:10.1038/s41929-018-0173-7Describing perovskite catalysts

    更新日期:2018-10-12
  • Electrochemical alternative to Fischer–Tropsch
    Nat. Catal. Pub Date : 2018-10-11
    David Raciti, Chao Wang

    Electrochemical alternative to Fischer–TropschElectrochemical alternative to Fischer–Tropsch, Published online: 11 October 2018; doi:10.1038/s41929-018-0160-zThe electroreduction of CO represents a promising approach toward artificial hydrocarbon synthesis, but its rate is limited by the sluggish transport of CO in aqueous electrolytes. Recent work shows how the issue can be circumvented by using gas diffusion electrodes.

    更新日期:2018-10-12
  • Enzymatic protection system
    Nat. Catal. Pub Date : 2018-10-11
    Jan-Stefan Völler

    Enzymatic protection systemEnzymatic protection system, Published online: 11 October 2018; doi:10.1038/s41929-018-0174-6Enzymatic protection system

    更新日期:2018-10-12
  • Improved CO2 reduction activity towards C2+ alcohols on a tandem gold on copper electrocatalyst
    Nat. Catal. Pub Date : 2018-10-11
    Carlos G. Morales-Guio, Etosha R. Cave, Stephanie A. Nitopi, Jeremy T. Feaster, Lei Wang, Kendra P. Kuhl, Ariel Jackson, Natalie C. Johnson, David N. Abram, Toru Hatsukade, Christopher Hahn, Thomas F. Jaramillo

    The discovery of materials for the electrochemical transformation of carbon dioxide into liquid fuels has the potential to impact large-scale storage of renewable energies and reduce carbon emissions. Here, we report the discovery of an electrocatalyst composed of gold nanoparticles on a polycrystalline copper foil (Au/Cu) that is highly active for CO2 reduction to alcohols. At low overpotentials, the Au/Cu electrocatalyst is over 100 times more selective for the formation of products containing C–C bonds versus methane or methanol, largely favouring the generation of alcohols over hydrocarbons. A combination of electrochemical testing and transport modelling supports the hypothesis that CO2 reduction on gold generates a high CO concentration on nearby copper, where CO is further reduced to alcohols such as ethanol and n-propanol under locally alkaline conditions. The bimetallic Au/Cu electrocatalyst exhibits synergistic activity and selectivity superior to gold, copper or AuCu alloys, and opens new possibilities for the development of CO2 reduction electrodes exploiting tandem catalysis mechanisms.

    更新日期:2018-10-12
  • Illuminated syngas
    Nat. Catal. Pub Date : 2018-10-11
    Davide Esposito

    Illuminated syngasIlluminated syngas, Published online: 11 October 2018; doi:10.1038/s41929-018-0172-8Illuminated syngas

    更新日期:2018-10-12
  • Highly efficient organic photocatalysts discovered via a computer-aided-design strategy for visible-light-driven atom transfer radical polymerization
    Nat. Catal. Pub Date : 2018-10-11
    Varun Kumar Singh, Changhoon Yu, Sachin Badgujar, Youngmu Kim, Yonghwan Kwon, Doyon Kim, Junhyeok Lee, Toheed Akhter, Gurunathan Thangavel, Lee Soon Park, Jiseok Lee, Paramjyothi C. Nandajan, Reinhold Wannemacher, Begoña Milián-Medina, Larry Lüer, Kwang S. Kim, Johannes Gierschner, Min Sang Kwon

    Organocatalysed photoredox-mediated atom transfer radical polymerization (O-ATRP) is a very promising polymerization method as it eliminates concerns associated with transition-metal contamination of polymer products. However, reducing the amount of catalyst and expanding the monomer scope remain major challenges in O-ATRP. Herein, we report a systematic computer-aided-design strategy to identify powerful visible-light photoredox catalysts for O-ATRP. One of our discovered organic photoredox catalysts controls the polymerization of methyl methacrylate at sub-ppm catalyst loadings (0.5 ppm—a very meaningful amount enabling the direct use of polymers without a catalyst removal process); that is, 100–1,000 times lower loadings than other organic photoredox catalysts reported so far. Another organic photoredox catalyst with supra-reducing power in an excited state and high redox stability facilitates the challenging polymerization of the non-acrylic monomer styrene, which is not successful using existing photoredox catalysts. This work provides access to diverse challenging organic/polymer syntheses and makes O-ATRP viable for many industrial and biomedical applications.

    更新日期:2018-10-12
  • World Food Day
    Nat. Catal. Pub Date : 2018-10-11

    16 October is World Food Day, and against a backdrop of increasing world hunger, we look at the role of science in making food production more distributed and more sustainable.

    更新日期:2018-10-12
  • Direct transformation of bulk copper into copper single sites via emitting and trapping of atoms
    Nat. Catal. Pub Date : 2018-10-08
    Yunteng Qu, Zhijun Li, Wenxing Chen, Yue Lin, Tongwei Yuan, Zhengkun Yang, Changming Zhao, Jing Wang, Chao Zhao, Xin Wang, Fangyao Zhou, Zhongbin Zhuang, Yuen Wu, Yadong Li

    Single-atom catalysts exhibit intriguing properties and receive widespread interest for their effectiveness in promoting a variety of catalytic reactions, making them highly desired motifs in materials science. However, common approaches to the synthesis of these materials often require tedious procedures and lack appropriate interactions between the metal atoms and supports. Here, we report a simple and practical strategy to access the large-scale synthesis of single-atom catalysts via direct atoms emitting from bulk metals, and the subsequent trapping on nitrogen-rich porous carbon with the assistance of ammonia. First, the ammonia coordinates with the copper atoms to form volatile Cu(NH3)x species based on the strong Lewis acid–base interaction. Then, following transportation under an ammonia atmosphere, the Cu(NH3)x species are trapped by the defects on the nitrogen-rich carbon support, forming the isolated copper sites. This strategy is readily scalable and has been confirmed as feasible for producing functional single-atom catalysts at industrial levels.

    更新日期:2018-10-09
  • A unique oxygen ligand environment facilitates water oxidation in hole-doped IrNiOx core–shell electrocatalysts
    Nat. Catal. Pub Date : 2018-10-08
    Hong Nhan Nong, Tobias Reier, Hyung-Suk Oh, Manuel Gliech, Paul Paciok, Thu Ha Thi Vu, Detre Teschner, Marc Heggen, Valeri Petkov, Robert Schlögl, Travis Jones, Peter Strasser

    The electro-oxidation of water to oxygen is expected to play a major role in the development of future electrochemical energy conversion and storage technologies. However, the slow rate of the oxygen evolution reaction remains a key challenge that requires fundamental understanding to facilitate the design of more active and stable electrocatalysts. Here, we probe the local geometric ligand environment and electronic metal states of oxygen-coordinated iridium centres in nickel-leached IrNi@IrOx metal oxide core–shell nanoparticles under catalytic oxygen evolution conditions using operando X-ray absorption spectroscopy, resonant high-energy X-ray diffraction and differential atomic pair correlation analysis. Nickel leaching during catalyst activation generates lattice vacancies, which in turn produce uniquely shortened Ir–O metal ligand bonds and an unusually large number of d-band holes in the iridium oxide shell. Density functional theory calculations show that this increase in the formal iridium oxidation state drives the formation of holes on the oxygen ligands in direct proximity to lattice vacancies. We argue that their electrophilic character renders these oxygen ligands susceptible to nucleophilic acid–base-type O–O bond formation at reduced kinetic barriers, resulting in strongly enhanced reactivities.

    更新日期:2018-10-09
  • Mapping out the key carbon–carbon bond-forming steps in Mn-catalysed C–H functionalization
    Nat. Catal. Pub Date : 2018-10-08
    L. Anders Hammarback, Ian P. Clark, Igor V. Sazanovich, Michael Towrie, Alan Robinson, Francis Clarke, Stephanie Meyer, Ian J. S. Fairlamb, Jason M. Lynam

    Detailed understanding of the mechanistic processes that underpin transition metal-catalysed reactions allows for the rational and de novo development of complexes with enhanced activity, efficacy and wider substrate scope. Directly observing bond-cleaving and -forming events underpinning a catalytic reaction is non-trivial as the species that facilitate these steps are frequently short-lived and present at low concentrations. Here, we describe how the photochemical activation of a manganese precatalyst, [Mn(ppy)(CO)4] (ppy = 2-phenylpyridine), results in selective loss of a carbonyl ligand simulating entry into the catalytic cycle for manganese-promoted C–H bond functionalization. Time-resolved infrared spectroscopy (on the ps–ms timescale) allows direct observation of the species responsible for the essential C–C bond formation step and an evaluation of the factors affecting its rate. This mechanistic information prompted the discovery of a new photochemically initiated manganese-promoted coupling of phenylacetylene with 2-phenylpyridine. This study provides unique insight into the mechanistic pathways underpinning catalysis by an Earth-abundant metal, manganese.

    更新日期:2018-10-09
  • Solar energy-driven lignin-first approach to full utilization of lignocellulosic biomass under mild conditions
    Nat. Catal. Pub Date : 2018-10-01
    Xuejiao Wu, Xueting Fan, Shunji Xie, Jinchi Lin, Jun Cheng, Qinghong Zhang, Liangyi Chen, Ye Wang

    The lignin-first concept offers an opportunity to utilize the entire lignocellulosic biomass efficiently. However, current conversion strategies rely on high-temperature hydrogenolysis by supported metal catalysts, leading to low-functionalized products or difficulty in separation of solid catalyst from cellulose/hemicellulose. Here, we report the fractionation and valorization of lignocellulose via solar energy-driven conversion of native lignin at room temperature. We found that cadmium sulfide quantum dots not only catalyse the cleavage of β-O-4 bonds in lignin models quantitatively but also are efficient for the conversion of native lignin within biomass into functionalized aromatics under visible light, while cellulose/hemicellulose remain almost intact. Further, the colloidal character of quantum dots enables their facile separation and recycling by a reversible aggregation–colloidization strategy. The β-O-4 bond in lignin is cleaved by an electron–hole coupled photoredox mechanism based on a Cα radical intermediate, in which both photogenerated electrons and holes participate in the reaction.

    更新日期:2018-10-02
  • Tandem copper hydride–Lewis pair catalysed reduction of carbon dioxide into formate with dihydrogen
    Nat. Catal. Pub Date : 2018-10-01
    Erik A. Romero, Tianxiang Zhao, Ryo Nakano, Xingbang Hu, Youting Wu, Rodolphe Jazzar, Guy Bertrand

    The reduction of CO2 into formic acid or its conjugate base, using dihydrogen, is an attractive process. While catalysts based on noble metals have shown high turnover numbers, the use of abundant first-row metals is underdeveloped. The key steps of the reaction are CO2 insertion into a metal hydride and regeneration of the metal hydride with H2, along with the concomitant production of formate. For the first step, copper is known as one of the most efficient metals, as shown by the numerous copper-catalysed carboxylation reactions, but this metal has difficulties activating H2 to achieve the second step. Here, we report a catalytic system involving a stable copper hydride that activates CO2, working in tandem with a Lewis pair that heterolytically splits H2. In this system, unprecedented turnover numbers for copper are obtained. Surprisingly, through a combination of stoichiometric and catalytic reactions, we show that classical Lewis pairs outperform frustrated Lewis pairs in this process.

    更新日期:2018-10-02
  • Publisher Correction: Computational optimization of electric fields for better catalysis design
    Nat. Catal. Pub Date : 2018-09-27
    Valerie Vaissier Welborn, Luis Ruiz Pestana, Teresa Head-Gordon

    Publisher Correction: Computational optimization of electric fields for better catalysis designPublisher Correction: Computational optimization of electric fields for better catalysis design, Published online: 27 September 2018; doi:10.1038/s41929-018-0161-yPublisher Correction: Computational optimization of electric fields for better catalysis design

    更新日期:2018-09-28
  • Publisher Correction: Artificial metalloenzymes: Reversible catalyst anchoring
    Nat. Catal. Pub Date : 2018-09-26
    Jun Okuda

    Publisher Correction: Artificial metalloenzymes: Reversible catalyst anchoringPublisher Correction: Artificial metalloenzymes: Reversible catalyst anchoring, Published online: 26 September 2018; doi:10.1038/s41929-018-0165-7Publisher Correction: Artificial metalloenzymes: Reversible catalyst anchoring

    更新日期:2018-09-26
  • Integrated tuneable synthesis of liquid fuels via Fischer–Tropsch technology
    Nat. Catal. Pub Date : 2018-09-17
    Jie Li, Yingluo He, Li Tan, Peipei Zhang, Xiaobo Peng, Anjaneyulu Oruganti, Guohui Yang, Hideki Abe, Ye Wang, Noritatsu Tsubaki

    To tune the product selectivity by controlling the complicated reaction path is a big challenge in Fischer–Tropsch synthesis. Here, we report an integrated catalytic process for the direct conversion of syngas (CO/H2) into different types of liquid fuels without subsequent hydrorefining post-treatments of Fischer–Tropsch waxes. Outstanding selectivities for gasoline, jet fuel and diesel fuel as high as 74, 72 and 58% are achieved, respectively, by only using mesoporous Y-type zeolites in combination with cobalt nanoparticles. The types of liquid fuels can be readily tuned by controlling the porosity and acid properties of the zeolites. We further build a new product-distribution model for the bifunctional catalysts, which do not obey the traditional Anderson–Schulz–Flory (ASF) distribution. The present work offers a simple and effective method for the direct synthesis of different types of liquid fuels.

    更新日期:2018-09-18
  • Unified structural motifs of the catalytically active state of Co(oxyhydr)oxides during the electrochemical oxygen evolution reaction
    Nat. Catal. Pub Date : 2018-09-12
    Arno Bergmann, Travis E. Jones, Elias Martinez Moreno, Detre Teschner, Petko Chernev, Manuel Gliech, Tobias Reier, Holger Dau, Peter Strasser

    Efficient catalysts for the anodic oxygen evolution reaction (OER) are critical for electrochemical H2 production. Their design requires structural knowledge of their catalytically active sites and state. Here, we track the atomic-scale structural evolution of well-defined CoOx(OH)y compounds into their catalytically active state during electrocatalytic operation through operando and surface-sensitive X-ray spectroscopy and surface voltammetry, supported by theoretical calculations. We find clear voltammetric evidence that electrochemically reducible near-surface Co3+–O sites play an organizing role for high OER activity. These sites invariably emerge independent of initial metal valency and coordination under catalytic OER conditions. Combining experiments and theory reveals the unified chemical structure motif as µ2-OH-bridged Co2+/3+ ion clusters formed on all three-dimensional cross-linked and layered CoOx(OH)y precursors and present in an oxidized form during the OER, as shown by operando X-ray spectroscopy. Together, the spectroscopic and electrochemical fingerprints offer a unified picture of our molecular understanding of the structure of catalytically active metal oxide OER sites.

    更新日期:2018-09-12
  • Chromism and catalysis shake hands
    Nat. Catal. Pub Date : 2018-09-12
    Anna Kubacka, Marcos Fernández-García

    Chromism and catalysis shake handsChromism and catalysis shake hands, Published online: 12 September 2018; doi:10.1038/s41929-018-0151-0Heterogeneous photocatalysts are rarely employed in industry for the synthesis of commodity chemicals due to efficiency problems. Now, a photochromic Bi2WO6–x/amorphous-BiOCl composite is reported, which features a remarkable activity for the photocatalytic oxidation of toluene into benzaldehyde and benzoic acid.

    更新日期:2018-09-12
  • On advances and challenges in biocatalysis
    Nat. Catal. Pub Date : 2018-09-12

    On advances and challenges in biocatalysisOn advances and challenges in biocatalysis, Published online: 12 September 2018; doi:10.1038/s41929-018-0157-7In this Editorial, we discuss recent advances and challenges in the field of biocatalysis and introduce some relevant work you will find in this issue of Nature Catalysis.

    更新日期:2018-09-12
  • Active learning across intermetallics to guide discovery of electrocatalysts for CO2 reduction and H2 evolution
    Nat. Catal. Pub Date : 2018-09-12
    Kevin Tran, Zachary W. Ulissi

    The electrochemical reduction of CO2 and H2 evolution from water can be used to store renewable energy that is produced intermittently. Scale-up of these reactions requires the discovery of effective electrocatalysts, but the electrocatalyst search space is too large to explore exhaustively. Here we present a theoretical, fully automated screening method that uses a combination of machine learning and optimization to guide density functional theory calculations, which are then used to predict electrocatalyst performance. We demonstrate the feasibility of this method by screening various alloys of 31 different elements, and thereby perform a screening that encompasses 50% of the d-block elements and 33% of the p-block elements. This method has thus far identified 131 candidate surfaces across 54 alloys for CO2 reduction and 258 surfaces across 102 alloys for H2 evolution. We use qualitative analyses to prioritize the top candidates for experimental validation.

    更新日期:2018-09-12
  • The feel of catalysis
    Nat. Catal. Pub Date : 2018-09-12
    Davide Esposito

    The feel of catalysisThe feel of catalysis, Published online: 12 September 2018; doi:10.1038/s41929-018-0155-9The feel of catalysis

    更新日期:2018-09-12
  • Iron holds it tight
    Nat. Catal. Pub Date : 2018-09-12
    Marçal Capdevila-Cortada

    Iron holds it tightIron holds it tight, Published online: 12 September 2018; doi:10.1038/s41929-018-0154-xIron holds it tight

    更新日期:2018-09-12
  • Catalytic conversion of solar to chemical energy on plasmonic metal nanostructures
    Nat. Catal. Pub Date : 2018-09-12
    Umar Aslam, Vishal Govind Rao, Steven Chavez, Suljo Linic

    The demonstrations of visible-light-driven chemical transformations on plasmonic metal nanostructures have led to the emergence of a new field in heterogeneous catalysis known as plasmonic catalysis. The excitement surrounding plasmonic catalysis stems from the ability to use the excitation of energetic charge carriers (as opposed to heat) to drive surface chemistry. This offers the opportunity to potentially discover new, more selective reaction pathways that cannot be accessed in temperature-driven catalysis. In this Review, we provide a fundamental overview of plasmonic catalysis with emphasis on recent advancements in the field. It is our objective to stress the importance of the underlying physical mechanisms at play in plasmonic catalysis and discuss possibilities and limitations in the field guided by these physical insights.

    更新日期:2018-09-12
  • Celebrating 100 years of the Rosenmund reaction
    Nat. Catal. Pub Date : 2018-09-12
    Andrei V. Iosub, Carl-Johan Wallentin, Joakim Bergman

    Celebrating 100 years of the Rosenmund reactionCelebrating 100 years of the Rosenmund reaction, Published online: 12 September 2018; doi:10.1038/s41929-018-0143-0This year marks a century since the pioneering work leading to what is now known as the Rosenmund reduction. We celebrate this landmark, reflecting upon the evolution of synthetic methodologies for reductive aldehyde synthesis from carboxylic acid derivatives and highlighting modern, improved strategies.

    更新日期:2018-09-12
  • Computational optimization of electric fields for better catalysis design
    Nat. Catal. Pub Date : 2018-09-03
    Valerie Vaissier Welborn, Luis Ruiz Pestana, Teresa Head-Gordon

    Although the ubiquitous role that long-ranged electric fields play in catalysis has been recognized, it is seldom used as a primary design parameter in the discovery of new catalytic materials. Here we illustrate how electric fields have been used to computationally optimize biocatalytic performance of a synthetic enzyme, and how they could be used as a unifying descriptor for catalytic design across a range of homogeneous and heterogeneous catalysts. Although focusing on electrostatic environmental effects may open new routes toward the rational optimization of efficient catalysts, much more predictive capacity is required of theoretical methods to have a transformative impact in their computational design — and thus experimental relevance — when using electric field alignments in the reactive centres of complex catalytic systems.

    更新日期:2018-09-04
  • A photochromic composite with enhanced carrier separation for the photocatalytic activation of benzylic C–H bonds in toluene
    Nat. Catal. Pub Date : 2018-09-03
    Xing Cao, Zheng Chen, Rui Lin, Weng-Chon Cheong, Shoujie Liu, Jian Zhang, Qing Peng, Chen Chen, Tong Han, Xuanjue Tong, Yu Wang, Rongan Shen, Wei Zhu, Dingsheng Wang, Yadong Li

    Photocatalysis based on the use of semiconducting materials is an emerging alternative to conventional thermochemical catalysis, and it has the potential to promote chemical synthesis under greener and milder conditions. However, heterogeneous photocatalytic organic reactions are still in their infancy, limited by the low-efficiency carrier separation of the currently available photocatalytic materials. Here, we report photochromic Bi2WO6–x/amorphous BiOCl (p-BWO) nanosheets, which, distinct from pristine Bi2WO6, show blue colouration upon visible light irradiation and are bleached by atmospheric oxygen. Studies on the microscopic structure of the material reveal the existence of abundant W(vi)O6–x units, which serve as the sites for the fast and continuous consumption of photogenerated electrons, thereby effectively facilitating the separation of electron–hole pairs. The prepared composite features a remarkable enhancement in performance for the photocatalytic oxidation of toluene with a conversion rate 166-fold higher compared with that of pristine Bi2WO6.

    更新日期:2018-09-04
  • Overall water splitting by Ta3N5 nanorod single crystals grown on the edges of KTaO3 particles
    Nat. Catal. Pub Date : 2018-09-03
    Zheng Wang, Yasunobu Inoue, Takashi Hisatomi, Ryo Ishikawa, Qian Wang, Tsuyoshi Takata, Shanshan Chen, Naoya Shibata, Yuichi Ikuhara, Kazunari Domen

    Although one-step-excitation overall water splitting on a particulate photocatalyst is a simple means of performing scalable solar-to-hydrogen energy conversion, there is a lack of photocatalysts with significant activity under visible light. Despite its superior visible-light absorption, the Ta3N5 photocatalyst has not accomplished overall water splitting due to strong charge recombination at defects. Here, we show rapid growth of Ta3N5 nanorods on lattice-matched cubic KTaO3 particles through the volatilization of potassium species during a brief nitridation process. The Ta3N5 nanorods generated selectively on the edge of KTaO3 are spatially separated and well-defined single crystals free from grain boundaries. When combined with the Rh/Cr2O3 co-catalyst, the single-crystal Ta3N5 nanorods split water into hydrogen and oxygen very efficiently under visible light and simulated sunlight. Our findings demonstrate the importance of nanostructured single-crystal photocatalysts free from structural defects in solar water splitting.

    更新日期:2018-09-04
  • Metabolic engineering of Escherichia coli for secretory production of free haem
    Nat. Catal. Pub Date : 2018-08-27
    Xin Rui Zhao, Kyeong Rok Choi, Sang Yup Lee

    Haem has widespread applications in healthcare and food supplement industries. Escherichia coli has previously been engineered to produce a small amount of haem intracellularly through the C4 pathway, requiring extraction for applications. Here we report secretory production of free haem by engineered E. coli strains, using the C5 pathway and the optimized downstream pathway for haem biosynthesis. Furthermore, knocking out ldhA, pta and also yfeX—encoding a putative haem-degrading enzyme—results in 7.88 mg l−1 of total haem with 1.26 mg l−1 of extracellular haem in flask cultivation. Fed-batch fermentations of the engineered strain overexpressing a haem exporter CcmABC from glucose only and glucose supplemented with l-glutamate secrete 73.4 and 151.4 mg l−1 of haem, respectively, which are 63.5% of 115.5 mg l−1 and 63.3% of 239.2 mg l−1 of total haem produced. The engineered E. coli strain reported here will be useful for microbial production of free haem.

    更新日期:2018-08-27
  • Lifetime improvement in methanol-to-olefins catalysis over chabazite materials by high-pressure H2 co-feeds
    Nat. Catal. Pub Date : 2018-08-24
    Sukaran S. Arora, Davy L. S. Nieskens, Andrzej Malek, Aditya Bhan

    Mitigating catalyst deactivation in the industrially deployed process of methanol-to-olefins conversion over HSAPO-34 is a critical challenge. Here, we demonstrate that lifetime in methanol-to-olefins catalysis over HSAPO-34 at sub-complete methanol conversion, as determined by the cumulative turnover capacity per Brønsted acid site towards hydrocarbon products in the effluent before complete catalyst deactivation (~15% carbon final conversion), can be enhanced with increasing efficacy (~2.8× to >70×) by co-feeding H2 at increasing partial pressures (400–3,000 kPa) in the influent with methanol compared with co-feeding helium at equivalent pressures. The lifetime improvement in the presence of high-pressure H2 co-feeds is observed to be more prominent at complete methanol conversion than at sub-complete conversion. The improvements in catalyst lifetime by co-feeding H2 are rendered without any deleterious effects on C2–C4 olefins selectivity, which remains ~85% carbon irrespective of the inlet H2 pressure. These observations can be rationalized based on the participation of H2 in hydrogen transfer reactions, and in effect, the interception of pathways that promote the formation of deactivation-inducing polycyclic species.

    更新日期:2018-08-26
  • High-rate electroreduction of carbon monoxide to multi-carbon products
    Nat. Catal. Pub Date : 2018-08-20
    Matthew Jouny, Wesley Luc, Feng Jiao

    Carbon monoxide electrolysis has previously been reported to yield enhanced multi-carbon (C2+) Faradaic efficiencies of up to ~55%, but only at low reaction rates. This is due to the low solubility of CO in aqueous electrolytes and operation in batch-type reactors. Here, we present a high-performance CO flow electrolyser with a well controlled electrode–electrolyte interface that can reach total current densities of up to 1 A cm–2, together with improved C2+ selectivities. Computational transport modelling and isotopic C18O reduction experiments suggest that the enhanced activity is due to a higher surface pH under CO reduction conditions, which facilitates the production of acetate. At optimal operating conditions, we achieve a C2+ Faradaic efficiency of ~91% with a C2+ partial current density over 630 mA cm–2. Further investigations show that maintaining an efficient triple-phase boundary at the electrode–electrolyte interface is the most critical challenge in achieving a stable CO/CO2 electrolysis process at high rates.

    更新日期:2018-08-20
  • Redox-switchable siderophore anchor enables reversible artificial metalloenzyme assembly
    Nat. Catal. Pub Date : 2018-08-20
    Daniel J. Raines, Justin E. Clarke, Elena V. Blagova, Eleanor J. Dodson, Keith S. Wilson, and Anne-K. Duhme-Klair

    Artificial metalloenzymes that contain protein-anchored synthetic catalysts are attracting increasing interest. An exciting, but still unrealized advantage of non-covalent anchoring is its potential for reversibility and thus component recycling. Here we present a siderophore–protein combination that enables strong but redox-reversible catalyst anchoring, as exemplified by an artificial transfer hydrogenase (ATHase). By linking the iron(iii)-binding siderophore azotochelin to an iridium-containing imine-reduction catalyst that produces racemic product in the absence of the protein CeuE, but a reproducible enantiomeric excess if protein bound, the assembly and reductively triggered disassembly of the ATHase was achieved. The crystal structure of the ATHase identified the residues involved in high-affinity binding and enantioselectivity. While in the presence of iron(iii), the azotochelin-based anchor binds CeuE with high affinity, and the reduction of the coordinated iron(iii) to iron(ii) triggers its dissociation from the protein. Thus, the assembly of the artificial enzyme can be controlled via the iron oxidation state.

    更新日期:2018-08-20
  • Bracing copper for the catalytic oxidation of C–H bonds
    Nat. Catal. Pub Date : 2018-08-10
    Luisa Ciano, Gideon J. Davies, William B. Tolman, Paul H. Walton

    A structural unit found in the active site of some copper proteins, the histidine brace, is comprised of an N-terminal histidine that chelates a single copper ion through its amino terminus NH2 and the π–N of its imidazole side chain. Coordination is completed by the τ-N of a further histidine side chain, to give an overall N3 T-shaped coordination at the copper ion. The histidine brace appears in several proteins, including lytic polysaccharide monooxygenases LPMOs and particulate methane monooxygenases pMMOs, both of which catalyse the oxidation of substrates with strong C–H bonds (bond dissociation enthalpies ~100 kcal mol–1). As such, the copper histidine brace is the focus of research aimed at understanding how nature catalyses the oxidation of unactivated C–H bonds. In this Perspective, we evaluate these studies, which further give bioinspired direction to coordination chemists in the design and preparation of small molecule copper oxidation catalysts.

    更新日期:2018-08-11
  • Air-stable [FeFe] hydrogenases
    Nat. Catal. Pub Date : 2018-08-10
    Jan-Stefan Völler

    Air-stable [FeFe] hydrogenases Air-stable [FeFe] hydrogenases, Published online: 10 August 2018; doi:10.1038/s41929-018-0137-y Air-stable [FeFe] hydrogenases

    更新日期:2018-08-11
  • Powering catalysis with supercomputers
    Nat. Catal. Pub Date : 2018-08-10

    Powering catalysis with supercomputers Powering catalysis with supercomputers, Published online: 10 August 2018; doi:10.1038/s41929-018-0135-0 Catalysis research has immensely benefited from the use of high-performance computing facilities. On the occasion of the twenty-fifth anniversary of the first Top500 list, we briefly revisit its content and evolution and the impact that supercomputers have had in catalysis.

    更新日期:2018-08-11
  • Complex terpenes in one pot
    Nat. Catal. Pub Date : 2018-08-10
    Dan Thomas Major

    Complex terpenes in one pot Complex terpenes in one pot, Published online: 10 August 2018; doi:10.1038/s41929-018-0130-5 The chemical synthesis of natural products, such as sesquiterpenes, is a daunting task due to their complexity and precise functionalization, and multiple synthetic and purification steps that reduce overall yields are usually required. Now, a highly efficient alternative approach using supramolecular chemistry has been proposed by Tiefenbacher and co-workers.

    更新日期:2018-08-11
  • Carbene capture in a myoglobin mutant
    Nat. Catal. Pub Date : 2018-08-10
    Emily H. Edwards, Kara L. Bren

    Carbene capture in a myoglobin mutant Carbene capture in a myoglobin mutant, Published online: 10 August 2018; doi:10.1038/s41929-018-0129-y Metalloprotein activity can be tuned by altering first- and second-sphere interactions with the metal ion or ions. Here, a non-canonical haem axial ligand is introduced into a myoglobin variant, modulating both. The resulting enhancement of cyclopropanation activity illustrates the utility of expanding the suite of available amino acids for biocatalyst engineering.

    更新日期:2018-08-11
  • Protocells realize their potential
    Nat. Catal. Pub Date : 2018-08-10
    Saidul Islam, Matthew W. Powner

    Protocells realize their potential Protocells realize their potential, Published online: 10 August 2018; doi:10.1038/s41929-018-0131-4 How the first metabolic network was organized to power a cell remains an enigma. Now, simple iron–sulfur peptides have been used to generate a pH-gradient across a protocell membrane by catalysing hydrogen peroxide reduction. This indicates that short peptides could have fulfilled the role of redox active metalloproteins in early life.

    更新日期:2018-08-11
  • Flowing through stacks
    Nat. Catal. Pub Date : 2018-08-10
    Davide Esposito

    Flowing through stacks Flowing through stacks, Published online: 10 August 2018; doi:10.1038/s41929-018-0136-z Flowing through stacks

    更新日期:2018-08-11
  • Selective and synergistic cobalt(iii)-catalysed three-component C–H bond addition to dienes and aldehydes
    Nat. Catal. Pub Date : 2018-08-06
    Jeffrey A. Boerth, Soham Maity, Sarah K. Williams, Brandon Q. Mercado, Jonathan A. Ellman

    Two-component C–H bond additions to a large variety of coupling partners have been developed with applications towards materials, natural product and drug synthesis. Sequential three-component C–H bond addition across two different coupling partners potentially enables the convergent synthesis of complex molecular scaffolds from simple precursors. Here, we report three-component Co(iii)-catalysed C–H bond additions to dienes and aldehydes that proceed with high regio- and stereoselectivity, resulting in two new carbon–carbon σ-bonds and four to six new stereocentres. The reaction relies on the synergistic reactivity of the diene and aldehyde, with neither undergoing C–H bond addition alone. A detailed mechanism is supported by X-ray structural characterization of a Co(iii)-allyl intermediate, observed transfer of stereochemical information, and kinetic isotope studies. The applicability of the method to biologically relevant molecules is exemplified by the rapid synthesis of the western fragment of the complex ionophore antibiotic lasalocid A.

    更新日期:2018-08-06
  • Enantioselective dearomative prenylation of indole derivatives
    Nat. Catal. Pub Date : 2018-08-06
    Hang-Fei Tu, Xiao Zhang, Chao Zheng, Min Zhu, Shu-Li You

    Prenylation is a ubiquitous process common to almost all living organisms, and a key transformation in organic synthesis. Dearomative prenylation reactions of tryptophan derivatives lead to various prenylated indoline alkaloids with diverse biological activities. However, enantioselective dearomative prenylations without a pre-installed stereogenic centre in the substrate have not been reported. Here, we show that a small molecule-based catalytic system derived from a commercially available palladium precursor and a chiral phosphoramidite ligand (allylphos) can catalyse the enantioselective dearomative prenylation of indole derivatives, which tolerates a much broader substrate scope than those of known enzymatic dearomative prenylation processes. Enantioselective dearomative geranylation and farnesylation reactions also proceed smoothly under the standard conditions. The concise total or formal syntheses of a series of natural products can be realized using this catalytic system. The mechanistic investigations provide deep insights for the further design of chiral ligands and catalysts for asymmetric reactions.

    更新日期:2018-08-06
  • Biocatalytic cascades driven by enzymes encapsulated in metal–organic framework nanoparticles
    Nat. Catal. Pub Date : 2018-08-06
    Wei-Hai Chen, Margarita Vázquez-González, Amani Zoabi, Raed Abu-Reziq, Itamar Willner

    Biocatalytic transformations in cells, such as enzyme cascades, involve complex networks proceeding in spatially confined microenvironments. Here, inspired by nature, we demonstrate effective biocatalytic cascades by the encapsulation of two or three enzymes, or enzyme/cofactor components, in zeolitic imidazolate framework-8 metal–organic framework nanoparticles (ZIF8-NMOFs) that act as nanoreactors. The integration of the two-enzyme system (glucose oxidase and horseradish peroxidase) or three-enzyme system (β-galactosidase, glucose oxidase and horseradish peroxidase) in the NMOFs leads to 7.5-fold and 5.3-fold enhancements in the activity of the catalytic cascades, respectively, compared with the bulk mixture of the catalysts in solution. In addition, the encapsulation of alcohol dehydrogenase, NAD+–polymer and lactate dehydrogenase in the NMOFs yields a coupled biocatalytic cascade involving coupled NAD+-dependent enzymes, leading to the catalytic reduction of pyruvic acid to lactic acid by ethanol.

    更新日期:2018-08-06
  • Extending the limits of Pt/C catalysts with passivation-gas-incorporated atomic layer deposition
    Nat. Catal. Pub Date : 2018-07-30
    Shicheng Xu, Yongmin Kim, Joonsuk Park, Drew Higgins, Shih-Jia Shen, Peter Schindler, Dickson Thian, J. Provine, Jan Torgersen, Tanja Graf, Thomas D. Schladt, Marat Orazov, Bernard Haochih Liu, Thomas F. Jaramillo, Fritz B. Prinz

    Controlling the morphology of noble metal nanoparticles during surface depositions is strongly influenced by precursor–substrate and precursor–deposit interactions. Depositions can be improved through a variety of means, including tailoring the surface energy of a substrate to improve precursor wettability, or by modifying the surface energy of the deposits themselves. Here, we show that carbon monoxide can be used as a passivation gas during atomic layer deposition to modify the surface energy of already deposited Pt nanoparticles to assist direct deposition onto a carbon catalyst support. The passivation process promotes two-dimensional growth leading to Pt nanoparticles with suppressed thicknesses and a more than 40% improvement in Pt surface-to-volume ratio. This approach to synthesizing nanoparticulate Pt/C catalysts achieved high Pt mass activities for the oxygen reduction reaction, along with excellent stability likely facilitated by strong catalyst–support interactions afforded by this synthetic technique.

    更新日期:2018-07-31
  • Publisher Correction: Streamlined hydrogen production from biomass
    Nat. Catal. Pub Date : 2018-07-30
    Ping Zhang, Yan-Jun Guo, Jianbin Chen, Yu-Rou Zhao, Jun Chang, Henrik Junge, Matthias Beller, Yang Li

    Publisher Correction: Streamlined hydrogen production from biomassPublisher Correction: Streamlined hydrogen production from biomass, Published online: 30 July 2018; doi:10.1038/s41929-018-0132-3Publisher Correction: Streamlined hydrogen production from biomass

    更新日期:2018-07-31
  • Prebiotic iron–sulfur peptide catalysts generate a pH gradient across model membranes of late protocells
    Nat. Catal. Pub Date : 2018-07-30
    Claudia Bonfio, Elisa Godino, Maddalena Corsini, Fabrizia Fabrizi de Biani, Graziano Guella, Sheref S. Mansy

    Prebiotic chemistry was likely mediated by metals, but how such prebiotic chemistry progressed into the metabolic-like networks needed to sustain life remains unclear. Here we experimentally delineate a potential path from prebiotically plausible iron–sulfur peptide catalysts to the types of pH gradients exploited by all known living organisms. Iron–sulfur peptides cooperatively accept electrons from NADH in a manner that is only partially mediated by ionic interactions. The electrons are then either passed to a terminal electron acceptor, such as hydrogen peroxide, or to an intermediate carrier, such as ubiquinone. The reduction of hydrogen peroxide leads to the production of hydroxide, which then contributes to the formation of a pH gradient across late protocell membranes. The data are consistent with the activity of prebiotic iron–sulfur peptide catalysts providing a selective advantage by equipping protocells with a pathway that connects catabolism to anabolism.

    更新日期:2018-07-31
  • Sesquiterpene cyclizations catalysed inside the resorcinarene capsule and application in the short synthesis of isolongifolene and isolongifolenone
    Nat. Catal. Pub Date : 2018-07-30
    Qi Zhang, Jan Rinkel, Bernd Goldfuss, Jeroen S. Dickschat, Konrad Tiefenbacher

    Terpenes constitute the largest class of natural products and serve as an important source for medicinal treatments. Despite constant progress in chemical synthesis, the construction of complex polycyclic sesqui- and diterpene scaffolds remains challenging. However, natural cyclase enzymes are able to form the whole variety of terpene structures from just a handful of linear precursors. Man-made catalysts able to mimic such natural enzymes are lacking. Here, we describe examples of sesquiterpene cyclizations inside an enzyme-mimicking supramolecular catalyst. This strategy allowed the formation of the tricyclic sesquiterpene isolongifolene in only four steps. The mechanism of the catalysed cyclization reaction was elucidated using 13C-labelling studies and density functional theory calculations.

    更新日期:2018-07-31
  • Pentamethylcyclopentadienyl rhodium(III)–chiral disulfonate hybrid catalysis for enantioselective C–H bond functionalization
    Nat. Catal. Pub Date : 2018-07-23
    Shun Satake, Takumaru Kurihara, Keisuke Nishikawa, Takuya Mochizuki, Manabu Hatano, Kazuaki Ishihara, Tatsuhiko Yoshino, Shigeki Matsunaga

    Though Cp*Rh(iii) complexes are prominent and versatile catalysts for C–H bond functionalization reactions, catalytic stereocontrol is difficult due to the lack of vacant coordination sites. Here, we report a hybrid strategy for inducing chirality without using previously reported chiral Cpx ligands. A preformed hybrid catalyst, [Cp*RhLN][6,6′-Br-(S)-BINSate], catalysed C–H activation and subsequent conjugate addition of 2-phenylpyridine derivatives to enones in good yield and enantioselectivity (enantiomeric ratio up to 95:5). In addition to 2-phenylpyridines, the conjugate addition of 6-arylpurines proceeded with an enantiomeric ratio of up to 91:9 using [Cp*RhLN][(R)-SPISate]. The results demonstrate that a chiral organic anion can efficiently control the enantioselectivity of Cp*Rh(iii)-catalysed C–H bond functionalization without a chiral Cpx ligand.

    更新日期:2018-07-24
  • Efficient electrocatalytic CO2 reduction on a three-phase interface
    Nat. Catal. Pub Date : 2018-07-23
    Jun Li, Guangxu Chen, Yangying Zhu, Zheng Liang, Allen Pei, Chun-Lan Wu, Hongxia Wang, Hye Ryoung Lee, Kai Liu, Steven Chu, Yi Cui

    Electrochemical CO2 reduction is a critical approach to reducing the globally accelerating CO2 emission and generating value-added products. Despite great efforts to optimize catalyst activity and selectivity, facilitating the catalyst accessibility to high CO2 concentrations while maintaining electrode durability remains a significant challenge. Here, we designed a catalytic system that mimics the alveolus structure in mammalian lungs with high gas permeability but very low water diffusibility, enabling an array of three-phase catalytic interfaces. Flexible, hydrophobic, nanoporous polyethylene membranes with high gas permeability were used to enable efficient CO2 access and a high local alkalinity on the catalyst surface at different CO2 flow rates. Such an alveolus-mimicking structure generates a high CO production Faradaic efficiency of 92% and excellent geometric current densities of CO production (25.5 mA cm−2) at −0.6 V versus the reversible hydrogen electrode, with a very thin catalyst thickness of 20−80 nm.

    更新日期:2018-07-24
  • Publisher Correction: A universal principle for a rational design of single-atom electrocatalysts
    Nat. Catal. Pub Date : 2018-07-20
    Haoxiang Xu, Daojian Cheng, Dapeng Cao, Xiao Cheng Zeng

    Publisher Correction: A universal principle for a rational design of single-atom electrocatalysts Publisher Correction: A universal principle for a rational design of single-atom electrocatalysts, Published online: 20 July 2018; doi:10.1038/s41929-018-0127-0 Publisher Correction: A universal principle for a rational design of single-atom electrocatalysts

    更新日期:2018-07-21
  • Capture and characterization of a reactive haem–carbenoid complex in an artificial metalloenzyme
    Nat. Catal. Pub Date : 2018-07-16
    Takahiro Hayashi, Matthias Tinzl, Takahiro Mori, Ute Krengel, Jonny Proppe, Janne Soetbeer, Daniel Klose, Gunnar Jeschke, Markus Reiher, Donald Hilvert

    Non-canonical amino acid ligands are useful for fine-tuning the catalytic properties of metalloenzymes. Here, we show that recombinant replacement of the histidine ligand proximal to haem in myoglobin with Nδ-methylhistidine enhances the protein’s promiscuous carbene-transfer chemistry, enabling efficient styrene cyclopropanation in the absence of reductant, even under aerobic conditions. The increased electrophilicity of the modified Fe(iii) centre, combined with subtle structural adjustments at the active site, allows direct attack of ethyl diazoacetate to produce a reactive carbenoid adduct, which has an unusual bridging Fe(iii)–C–N(pyrrole) configuration as shown by X-ray crystallography. Quantum chemical calculations suggest that the bridged complex equilibrates with the more reactive end-on isomer, ensuring efficient cyclopropanation. These findings underscore the potential of non-canonical ligands for extending the capabilities of metalloenzymes by opening up new reaction pathways and facilitating the characterization of reactive species that would not otherwise accumulate.

    更新日期:2018-07-18
  • A happy couple
    Nat. Catal. Pub Date : 2018-07-12
    Frank Marken, Steven D. Bull

    A happy couple A happy couple, Published online: 12 July 2018; doi:10.1038/s41929-018-0113-6 Pairing electrosynthetic anode and cathode processes (either convergent or divergent) is essential to maximize energy usage/sustainability and to minimize waste. New approaches to pairing in electrosynthesis are needed and the use of a palladium film membrane by Berlinguette and co-workers represents an effective paired reactor prototype that couples electrosynthesis with chemical catalysis.

    更新日期:2018-07-12
  • Enhancing DNA sequencing
    Nat. Catal. Pub Date : 2018-07-12
    Jan-Stefan Völler

    Enhancing DNA sequencing Enhancing DNA sequencing, Published online: 12 July 2018; doi:10.1038/s41929-018-0120-7 Enhancing DNA sequencing

    更新日期:2018-07-12
  • Synthesis of reaction‐adapted zeolites as methanol-to-olefins catalysts with mimics of reaction intermediates as organic structure‐directing agents
    Nat. Catal. Pub Date : 2018-07-12
    Chengeng Li, Cecilia Paris, Joaquín Martínez-Triguero, Mercedes Boronat, Manuel Moliner, Avelino Corma

    Catalysis with enzymes and zeolites have in common the presence of well-defined single active sites and pockets/cavities where the reaction transition states can be stabilized by longer-range interactions. We show here that for a complex reaction, such as the conversion of methanol-to-olefins (MTO), it is possible to synthesize reaction-adapted zeolites by using mimics of the key molecular species involved in the MTO mechanism. Effort has focused on the intermediates of the paring mechanism because the paring is less favoured energetically than the side-chain route. All the organic structure-directing agents based on intermediate mimics crystallize cage-based small-pore zeolitic materials, all of them capable of performing the MTO reaction. Among the zeolites obtained, RTH favours the whole reaction steps following the paring route and gives the highest propylene/ethylene ratio compared to traditional CHA-related zeolites (3.07 and 0.86, respectively).

    更新日期:2018-07-12
  • The importance of industrial publications
    Nat. Catal. Pub Date : 2018-07-12

    The importance of industrial publications The importance of industrial publications, Published online: 12 July 2018; doi:10.1038/s41929-018-0119-0 Industrial publications are a very valuable and multifaceted tool for the wider catalysis community; they can foster the productive collaboration of university and corporate research laboratories, an essential partnership for the solution of important societal problems

    更新日期:2018-07-12
  • Fixation of gaseous CO2 by reversing a decarboxylase for the biocatalytic synthesis of the essential amino acid l-methionine
    Nat. Catal. Pub Date : 2018-07-12
    Julia Martin, Lukas Eisoldt, Arne Skerra

    The use of CO2 as a building block for the synthesis of bulk chemicals appears highly attractive but has not been realized in industrial biotechnology due to the complexity and costly energy balance of conventional anabolic biosynthesis. Here, we describe the biocatalytic preparation of l-methionine from the abundant industrial intermediate methional under direct incorporation of CO2 by reversing the catabolic Ehrlich pathway. Despite unfavourable chemical equilibrium (1/554 M−1), the decarboxylase KdcA revealed half-maximal activity for its reverse reaction at astonishingly low CO2 pressure (320 kPa). Accordingly, it was possible to synthesize l-methionine under a 2 bar CO2 atmosphere when coupled to an energetically favourable transaminase or amino acid dehydrogenase reaction. Similarly, l-leucine and l-isoleucine were prepared via biocatalytic carboxylation of 3- or 2-methylbutanal, respectively. Our findings open a biotechnological route towards industrial products and enable further syntheses involving the fixation of gaseous CO2 by simply applying decarboxylases in the reverse mode.

    更新日期:2018-07-12
  • Rational design of zeolite catalysts
    Nat. Catal. Pub Date : 2018-07-12
    Jeffrey D. Rimer

    Rational design of zeolite catalysts Rational design of zeolite catalysts, Published online: 12 July 2018; doi:10.1038/s41929-018-0114-5 The identification of organic structure-directing agents capable of tailoring the physicochemical properties of microporous materials has remained a challenge. Now, a unique methodology to design organic mimics of reaction intermediates provides a route to optimize the selectivity of zeolite catalysts.

    更新日期:2018-07-12
  • Separable Suzuki
    Nat. Catal. Pub Date : 2018-07-12
    Enda Bergin

    Separable Suzuki Separable Suzuki, Published online: 12 July 2018; doi:10.1038/s41929-018-0121-6 Separable Suzuki

    更新日期:2018-07-12
  • Catalysts for nitrogen reduction to ammonia
    Nat. Catal. Pub Date : 2018-07-12
    Shelby L. Foster, Sergio I. Perez Bakovic, Royce D. Duda, Sharad Maheshwari, Ross D. Milton, Shelley D. Minteer, Michael J. Janik, Julie N. Renner, Lauren F. Greenlee

    The production of synthetic ammonia remains dependent on the energy- and capital-intensive Haber–Bosch process. Extensive research in molecular catalysis has demonstrated ammonia production from dinitrogen, albeit at low production rates. Mechanistic understanding of dinitrogen reduction to ammonia continues to be delineated through study of molecular catalyst structure, as well as through understanding the naturally occurring nitrogenase enzyme. The transition to Haber–Bosch alternatives through robust, heterogeneous catalyst surfaces remains an unsolved research challenge. Catalysts for electrochemical reduction of dinitrogen to ammonia are a specific focus of research, due to the potential to compete with the Haber–Bosch process and reduce associated carbon dioxide emissions. However, limited progress has been made to date, as most electrocatalyst surfaces lack specificity towards nitrogen fixation. In this Review, we discuss the progress of the field in developing a mechanistic understanding of nitrogenase-promoted and molecular catalyst-promoted ammonia synthesis and provide a review of the state of the art and scientific needs for heterogeneous electrocatalysts.

    更新日期:2018-07-12
  • Sinter-resistant metal nanoparticle catalysts achieved by immobilization within zeolite crystals via seed-directed growth
    Nat. Catal. Pub Date : 2018-07-09
    Jian Zhang, Liang Wang, Bingsen Zhang, Haishuang Zhao, Ute Kolb, Yihan Zhu, Lingmei Liu, Yu Han, Guoxiong Wang, Chengtao Wang, Dang Sheng Su, Bruce C. Gates, Feng-Shou Xiao

    Supported metal nanoparticle catalysts are widely used in industry but suffer from deactivation resulting from metal sintering and coke deposition at high reaction temperatures. Here, we show an efficient and general strategy for the preparation of supported metal nanoparticle catalysts with very high resistance to sintering by fixing the metal nanoparticles (platinum, palladium, rhodium and silver) with diameters in the range of industrial catalysts (0.8–3.6 nm) within zeolite crystals (metal@zeolite) by means of a controllable seed-directed growth technique. The resulting materials are sinter resistant at 600–700 °C, and the uniform zeolite micropores allow for the diffusion of reactants enabling contact with the metal nanoparticles. The metal@zeolite catalysts exhibit long reaction lifetimes, outperforming conventional supported metal catalysts and commercial catalysts consisting of metal nanoparticles on the surfaces of solid supports during the catalytic conversion of C1 molecules, including the water-gas shift reaction, CO oxidation, oxidative reforming of methane and CO2 hydrogenation.

    更新日期:2018-07-10
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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