Li Haobo, Xiao Jianping, Fu Qiang, Bao Xinhe
State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China.
State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
Proc Natl Acad Sci U S A. 2017 Jun 6;114(23):5930-5934. doi: 10.1073/pnas.1701280114. Epub 2017 May 22.
Confined microenvironments formed in heterogeneous catalysts have recently been recognized as equally important as catalytically active sites. Understanding the fundamentals of confined catalysis has become an important topic in heterogeneous catalysis. Well-defined 2D space between a catalyst surface and a 2D material overlayer provides an ideal microenvironment to explore the confined catalysis experimentally and theoretically. Using density functional theory calculations, we reveal that adsorption of atoms and molecules on a Pt(111) surface always has been weakened under monolayer graphene, which is attributed to the geometric constraint and confinement field in the 2D space between the graphene overlayer and the Pt(111) surface. A similar result has been found on Pt(110) and Pt(100) surfaces covered with graphene. The microenvironment created by coating a catalyst surface with 2D material overlayer can be used to modulate surface reactivity, which has been illustrated by optimizing oxygen reduction reaction activity on Pt(111) covered by various 2D materials. We demonstrate a concept of confined catalysis under 2D cover based on a weak van der Waals interaction between 2D material overlayers and underlying catalyst surfaces.
最近，人们认识到在多相催化剂中形成的受限微环境与催化活性位点同样重要。理解受限催化的基本原理已成为多相催化中的一个重要课题。催化剂表面与二维材料覆盖层之间明确界定的二维空间为从实验和理论上探索受限催化提供了理想的微环境。通过密度泛函理论计算，我们发现，在单层石墨烯下，原子和分子在Pt(111)表面的吸附总是会减弱，这归因于石墨烯覆盖层与Pt(111)表面之间二维空间中的几何约束和限制场。在覆盖有石墨烯的Pt(110)和Pt(100)表面也发现了类似的结果。用二维材料覆盖层包覆催化剂表面所产生的微环境可用于调节表面反应性，这已通过优化各种二维材料覆盖的Pt(111)上的氧还原反应活性得到了说明。基于二维材料覆盖层与下层催化剂表面之间的弱范德华相互作用，我们展示了二维覆盖下的受限催化概念。
