Boosting Support Reducibility and Metal Dispersion by Exposed Surface Atom Control for Highly Active Supported Metal Catalysts

Abstract

For oxide-supported metal catalysts, support reducibility and metal dispersion are the key factors to determine the activity and selectivity in many essential reactions involving redox process. Herein, we tuned the exposed surface atoms of the catalyst by facet control and doping methods, which were simultaneously applied to boost the reducibility and metal dispersion of an oxide support. Pd supported on Cu-doped CeO2 (Pd/CDC) for water–gas shift reaction (WGSR) was considered a model system; Cu was doped into the cubic and octahedral CeO2 enclosed with (100) and (111) facets, respectively. By a systematic combination of density functional theory calculations and experimental analyses, the WGSR activity of the Pd/CDC cube was verified to synergistically increase by more than just the sum of the morphology and Cu doping effects. The effect of each tuning method on the activity was further investigated from a mechanistic perspective. This work presents a rational design knowledge to enhance the catalytic activity that can be extended to a wide range of supported metal systems.