Atomic metal catalysts for maximum performance of surface reactions

Abstract

Maximizing the catalytic performance and the use of precious metals (Pt, Pd and Rh) has been actively pursued in heterogeneous catalysis. In the present decade, single-atom catalysts, in which all the metal atoms are spatially isolated on a support with 100% metal dispersion, have received much attention. However, existing single-atom catalysts contain many critical limitations, such as lack of ensemble sites, highly oxidized state and poor durability. In this study, metal atom arrangement of atomic catalysts was precisely controlled to the isolated single-atom or neighboring ensemble structure. Specifically, strong interaction between defective support and metal atom, controlling the impregnation rate of metal atom strategies, and metal atom redispersion by hydrothermal treatment were designed and applied to synthesize the atomic catalysts. In addition, electronic state of atomic catalysts was controlled from oxidized to metallic state while maintaining the atomic structure. The metal atom arrangement and electronic state of the fabricated atomic catalysts were clearly investigated using various characterization tools. Geometric structure and electronic state controlled atomic catalysts exhibited superior activity and durability for surface reactions, and can provide a solid platform for performance studies in heterogeneous catalysis.