Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé (ICPEES), ECPM, UMR 7515 CNRS - Université de Strasbourg , 25 rue Becquerel, Strasbourg 67087 Cedex 02, France.
Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR 7504 du CNRS, Université de Strasbourg , 23 rue du Loess, Strasbourg 67037 Cedex 08, France.
ACS Appl Mater Interfaces. 2017 Oct 4;9(39):34256-34268. doi: 10.1021/acsami.7b10638. Epub 2017 Sep 21.
Cobalt particles dispersed on an oxide support form the basis of many important heterogeneous catalysts. Strong interactions between cobalt and the support may lead to irreducible cobalt oxide formation, which is detrimental for the catalytic performance. Therefore, several strategies have been proposed to enhance cobalt reducibility, such as alloying with Pt or utilization of nonoxide supports. In this work, we fabricate bimetallic PtCo supported on graphene-coated ZnO with enhanced cobalt reducibility. By employing a model/planar catalyst formulation, we show that the surface reduction of cobalt oxide is substantially enhanced by the presence of the graphene support as compared to bare ZnO. Stimulated by these findings, we synthesized a realistic powder catalyst consisting of PtCo particles grafted on graphene-coated ZnO support. We found that the addition of graphene coating enhances the surface reducibility of cobalt, fully supporting the results obtained on the model system. Our study demonstrates that realistic catalysts with designed properties can be developed on the basis of insights gained from model catalytic formulation.
钴颗粒分散在氧化物载体上，构成了许多重要的多相催化剂的基础。钴与载体之间的强相互作用可能导致不可还原的氧化钴形成，这对催化性能是有害的。因此，已经提出了几种提高钴还原度的策略，例如与 Pt 合金化或利用非氧化物载体。在这项工作中，我们制备了负载在石墨烯包覆 ZnO 上的双金属 PtCo，以提高钴的还原度。通过采用模型/平面催化剂配方，我们表明与裸 ZnO 相比，石墨烯载体的存在极大地增强了钴氧化物的表面还原。受这些发现的启发，我们合成了一种由负载在石墨烯包覆 ZnO 载体上的 PtCo 颗粒组成的实际粉末催化剂。我们发现，石墨烯涂层的添加增强了钴的表面还原度，完全支持了在模型体系中获得的结果。我们的研究表明，可以在从模型催化配方中获得的见解的基础上，开发具有设计性能的实际催化剂。
