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Epitaxial and atomically thin graphene–metal hybrid catalyst films: the dual role of graphene as the support and the chemically-transparent protective cap†
Energy & Environmental Science ( IF 32.5 ) Pub Date : 2018-04-20 00:00:00 , DOI: 10.1039/c8ee00539g
Ali Abdelhafiz 1, 2, 3, 4 , Adam Vitale 1, 2, 3, 4 , Parker Buntin 1, 2, 3, 4 , Ben deGlee 1, 2, 3, 4 , Corey Joiner 1, 2, 3, 4 , Alex Robertson 5, 6, 7, 8 , Eric M. Vogel 1, 2, 3, 4 , Jamie Warner 5, 6, 7, 8 , Faisal M. Alamgir 1, 2, 3, 4
Affiliation  

In this study, we demonstrate dual roles for graphene, as both a platform for large-area, fully-wetted growth of two-dimensional Pt films that are one monolayer to several multilayers thick, while also serving as a ‘chemically transparent’ barrier to catalytic deactivation wherein graphene does not restrict the access of the reactants but does block Pt from dissolution or agglomeration. Using these architectures, we show that it is possible to simultaneously achieve enhanced catalytic activity and unprecedented stability, retaining full activity beyond 1000 cycles, for the canonical oxygen reduction reaction (ORR). Using high resolution TEM, AFM, X-ray photoemission/absorption spectroscopy (XPS/XAS), Raman, and electrochemical methods, we show that, due to intimate graphene–Pt epitaxial contact, Pt_ML/GR hybrid architectures are able to induce a compressive strain on the supported Pt adlayer and increase catalytic activity for ORR. With no appreciable Pt loss or agglomeration observed with the GR/Pt_ML catalysts after 1000 ORR cycles, our results open the door to using similar graphene-templated/graphene-capped hybrid catalysts as means to improve catalyst lifetime without a necessary compromise to their activity. More broadly, the epitaxial growth made possible by the room-temperature, wetted synthesis approach, should allow for efficient transfer of charge, strain, phonons and photons, impacting not just catalysis, but also electronic, thermoelectric and optical materials.

中文翻译:

外延和原子薄的石墨烯-金属杂化催化剂膜:石墨烯作为载体和化学透明保护帽的双重作用

在这项研究中,我们证明了石墨烯的双重作用,既是一个大面积的,全润湿生长的二维Pt膜的平台,该二维Pt膜从单层到几层厚,同时还充当了“化学透明”的屏障催化失活,其中石墨烯不限制反应物的进入,但可以阻止Pt溶解或结块。使用这些体系结构,我们表明对于规范的氧还原反应(ORR),可以同时实现增强的催化活性和空前的稳定性,保持超过1000个循环的全部活性。使用高分辨率TEM,AFM,X射线光发射/吸收光谱(XPS / XAS),拉曼光谱和电化学方法,我们表明,由于石墨烯-Pt外延紧密接触,Pt_ML / GR混合体系结构能够在负载的Pt附加层上诱导压缩应变,并提高ORR的催化活性。在1000次ORR循环后,使用GR / Pt_ML催化剂未观察到明显的Pt损失或团聚,我们的结果为使用类似的石墨烯模板/石墨烯封端的杂化催化剂作为延长催化剂寿命的途径打开了大门,而无需对其活性进行必要的折衷。更广泛地说,通过室温湿法合成方法实现的外延生长应允许电荷,应变,声子和光子的有效转移,不仅影响催化,而且影响电子,热电和光学材料。在1000次ORR循环后,使用GR / Pt_ML催化剂未观察到明显的Pt损失或团聚,我们的结果为使用类似的石墨烯模板/石墨烯封端的杂化催化剂作为延长催化剂寿命的途径打开了大门,而无需对其活性进行必要的折衷。更广泛地说,通过室温湿法合成方法实现的外延生长应允许电荷,应变,声子和光子的有效转移,不仅影响催化,而且影响电子,热电和光学材料。在1000次ORR循环后,使用GR / Pt_ML催化剂未观察到明显的Pt损失或团聚,我们的结果为使用类似的石墨烯模板/石墨烯封端的杂化催化剂作为延长催化剂寿命的途径打开了大门,而无需对其活性进行必要的折衷。更广泛地说,通过室温湿法合成方法实现的外延生长应允许电荷,应变,声子和光子的有效转移,不仅影响催化,而且影响电子,热电和光学材料。
更新日期:2018-04-20
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