Photodriven Catalytic Hydrogenation of CO2 to CH4 with Nearly 100% Selectivity over Ag25 Clusters

The conversion of chemically inert carbon dioxide and its photoreduction to value-added products have attracted enormous attention as an intriguing prospect for utilizing the principal greenhouse gas CO2. Herein, we explore the use of Ag-25 clusters with well-defined atomic structures for high-selectivity photocatalytic hydrogenation of CO2 to methane. Ag-25 clusters, with molecular-like properties and surface plasmon resonance, exhibit competitive catalytic activity for light-driven CO2 reduction that yield an almost 100% product selectivity of methane at a relatively mild temperature (100 degrees C). DFT calculations reveal that the absorption of CO2 on Ag-25 clusters is energetically favorable. The methanation of the Ag-25 cluster catalyst has been investigated by operando infrared spectroscopy, verifying that methane was produced through a -H-assisted multielectron reaction pathway via the transformation of formyl and formaldehyde species to form surface CHx. This work presents a highly efficient strategy for high-performance CO2 methanation via well-defined metal cluster catalysts.

Automated summary

This study investigates the high-selectivity photocatalytic hydrogenation of CO2 to methane using Ag-25 clusters with well-defined atomic structures. The DFT calculations show that CO2 absorption on Ag-25 clusters is energetically favorable, while operando infrared spectroscopy confirms the production of methane through a multi-electron reaction pathway. The work presents a highly efficient strategy for CO2 methanation using well-defined metal cluster catalysts.