Porous Metal Nanocrystal Catalysts: Can Crystalline Porosity Enable Catalytic Selectivity?

Abstract

Catalytic selectivity is a central issue in the efficiency of catalytic processes. A large number of strategies have been developed to improve the catalytic selectivity of metal catalysts at the atomic and molecular levels, for instance, alloying secondary elements, fabricating metal-support interactions, and introducing surface ligands. Recently, macro/mesoscopic pores and cavities have been demonstrated as an alternative route to promote catalytic selectivity of metal nanocrystal catalysts. The promotion effects of continuous crystalline porosity include (1) more catalytically active sites that accelerate the favorable catalytic routes to targeted products, (2) confined spaces that increase the retention time of key intermediates and remarkably promote the selective catalysis toward desired products, and (3) an optimized electronic structure and coordination environment of active metal sites that tailor the reaction trends of selective catalysis toward desired products. In this minireview, we summarize recent advances in porosity-enabled catalytic selectivity of metal nanocrystal catalysts with focused discussions of CO2 reduction electrocatalysis and selective hydrogenation reactions. The mechanisms that allow for the continuous porosity that enables the catalytic selectivity of metal nanocrystal catalysts are discussed in detail. We end this minireview by proposing current challenges and offering future opportunities in this research field.