Angstrom-Scale-Distance Dependent Synergy in Cluster via Atomby-Atom Regulation for Enhanced Photocatalytic CO2 Reduction

Abstract

Constructing multi active sites catalyst with suitable atomic distance to put synergistic enhancement catalysis effect into great play is still challenging. Multi atom cluster with well-defined, uniform, and controllable atomic configuration and distance provides an unprecedented opportunity. Herein, we designed and synthesized a series of atomically precise Pdx supported on TiO2 (Pdx-TiO2, x = 1, 2, 3, and 5) to elucidate the concept of angstrom-scale-distance dependent synergy catalysis via atom-by-atom regulation. Benefiting from enhanced light utilization, CO2 adsorption, and photoinduced charge transfer and separation capability, Pd3-TiO2 exhibits the best activity in pure H2O mediated photocatalytic CO2 reduction (CO2RR), with CO/CH4 yield of 86.09/42.94 μmol gcat -1 h -1 . The combination of precise structural characterization, ex/in situ photoelectrochemical test, and theoretical calculations provides in-depth insights into the superior CO2RR activity of Pd3-TiO2, that is the appropriate atomic distance maximizes the interaction between Pd atoms and enhances synergistic effect, thereby reducing rate determining step energy barrier for CO2-to-CO as well as promoting the *CO key intermediate formation for CH4 generation. This work illuminates a novel avenue to fully utilize the synergistic effect between multiple active sites through atomic spacing adjustment for advanced catalysts design.