MOF-derived Cu&+-OV-Ce active sites for enhanced CO2 hydrogenation

Abstract

Highly dispersed Cu species have attracted much attention due to their high activity and selectivity in CO₂ hydrogenation; however, sintering-induced deactivation under a thermal reductive atmosphere remains a challenge. Herein, we employ a Ce-MOF-derived inorganic framework as a template to adsorb Cu ions, followed by pyrolysis to form CeO₂ lattice-confined ultra-stable Cu single-atom catalysts (named Cu-CeO₂-4-600). Cu-CeO₂-4-600 exhibited excellent performance under high-temperature CO₂ hydrogenation, with 100% CO selectivity and 33% CO₂ conversion during 86 h of continuous operation. Atomic structure characterization reveals that Cu single atoms are incorporated into the CeO₂ lattice that induces a critical lattice confinement and effectively suppresses the sintering of Cu single atoms. Additionally, the electronic structure analysis further demonstrated that the introduction of Cu significantly increases the oxygen vacancy (O_V) concentration, leading to the formation of Cu^&+-O_V-Ce active species. These two improvements collectively enhance the CO₂ hydrogenation performance. This study offers a promising strategy for constructing highly active and stable catalytic sites in MOF-derived materials.