Increasing demand for sustainable energy sources continues to motivate the development of new catalytic processes that store intermittent energy in the form of chemical bonds. In this context, photosynthetic organisms harvest light to drive dark reactions reducing carbon dioxide, an abundant and accessible carbon source, to store solar energy in the form of glucose and other biomass feedstocks. Inspired by this biological process, the field of artificial photosynthesis aims to store renewable energy in chemical bonds spanning fuels, foods, medicines, and materials using light, water, and CO2 as the primary chemical feedstocks, with the added benefit of mitigating the accumulation of CO2 as a greenhouse gas in the atmosphere. As such, devising new catalyst platforms for transforming CO2 into value-added chemical products is of importance. Historically, catalyst design for artificial photosynthesis has been approached from the three traditional fields of catalysis: molecular, materials, and biological. In this Account, we show progress from our laboratory in constructing new hybrid catalysts for artificial photosynthesis that draw upon design concepts from all three of these traditional fields of catalysis and blur the boundaries between them. Starting with molecular catalysis, we incorporated biological design elements that are prevalent in enzymes into synthetic systems. Specifically, we demonstrated that proper positioning of intramolecular hydrogen bond donors or addition of intermolecular multipoint hydrogen bond donors with classic iron porphyrin and nickel cyclam platforms can substantially increase rates of CO2 reduction and break electronic scaling relationships. In parallel, we incorporated a key materials design element, namely, high surface area and porosity for maximizing active site exposure, into molecular systems. A supramolecular porous organic cage molecule was synthesized with iron porphyrin building blocks, and the porosity was observed to facilitate substrate and charge transport through the catalyst film. In turn, molecular design elements can be incorporated into materials catalysts for CO2 reduction. First, we utilized molecular synthons in a bottom-up reticular approach to drive polymerization/assembly into a bulk framework material. Second, we established an organometallic approach in which molecular ligands, including chelating ones, are adsorbed onto a bulk inorganic solid to create and tune new active sites on surfaces. Finally, we describe two examples in which molecular, materials, and biological design elements are all integrated to catalyze the reduction of CO2 into CH4 using a hybrid biological-materials interface with sustainably generated H2 as the reductant or to reduce CO into value-added C2 products acetate and ethanol using a hybrid molecular-materials interface to construct a biomimetic, bimetallic active site. Taken together, our program in catalysis for energy and sustainability has revealed that combining more conventional design strategies in synergistic ways can lead to advances in artificial photosynthesis.

中文翻译：

---

人工光合作用的杂化催化剂：分子，材料和生物催化的合并方法。

对可持续能源的需求不断增长，继续推动着新催化工艺的发展，这些工艺以化学键的形式存储间歇性能量。在这种情况下，光合作用生物收获光以驱动黑暗反应，从而减少二氧化碳（一种丰富而可及的碳源），以葡萄糖和其他生物质原料的形式存储太阳能。受此生物过程的启发，人工光合作用的目的是将可再生能源存储在燃料，食品，药物和材料的化学键中，这些化学键使用光，水和二氧化碳作为主要化学原料，并具有减轻生物累积的额外好处。 CO2作为大气中的温室气体。因此，设计新的催化剂平台以将CO2转化为增值化学产品非常重要。从历史上看，已经从三个传统的催化领域（分子，材料和生物）研究了用于人工光合作用的催化剂设计。在此报告中，我们将展示我们实验室在构建用于人工光合作用的新型混合催化剂方面的进展，这些催化剂借鉴了所有这三个传统催化领域的设计理念，并模糊了它们之间的界限。从分子催化开始，我们将酶中普遍存在的生物学设计元素纳入了合成系统。具体而言，我们证明了分子内氢键供体的正确定位或经典铁卟啉和镍基西酰胺平台的分子间多点氢键供体的添加可以显着提高CO2还原率并打破电子结垢关系。同时，我们将关键的材料设计元素（即高表面积和高孔隙率）用于分子系统，以最大程度地增加活性位点的暴露。合成了具有铁卟啉结构单元的超分子多孔有机笼分子，并观察到孔隙率有利于基质和电荷通过催化剂膜传输。反过来，可以将分子设计元素结合到材料催化剂中以减少CO2。首先，我们以自下而上的网状结构方法利用分子合成子来驱动聚合/组装成整体骨架材料。其次，我们建立了一种有机金属方法，其中分子配体（包括螯合剂）被吸附到大量无机固体上，以在表面上产生和调节新的活性位点。最后，我们描述两个例子，其中分子，材料，和生物设计元素全部集成在一起，以使用可持续产生的H2作为还原剂的混合生物材料界面催化将CO2还原为CH4，或使用混合分子材料界面将CO还原为增值C2产品乙酸和乙醇。构建仿生的双金属活性位点。两者合计，我们在能源和可持续性催化方面的计划表明，以协同方式结合更常规的设计策略可以促进人工光合作用的发展。