Hierarchically porous bimetallic oxide derived from a metal-organic framework for the promotion of catalytic CO2 chemical fixation

Abstract

Chemical carbon dioxide (CO2) fixation over heterogenous catalysts under more realistic conditions enables the acceleration of the global carbon cycle. Despite the recent advances, many catalysts often suffer from chemical lability, mass transfer resistance, as well as single catalytic species. To this end, this work demonstrates a metal-organic framework (MOF)-templated thermolysis to give bimetallic oxides, CuxZny-BMOs, featuring hierarchically porous structures. By varying the initial molar ratio of Cu/Zn, the local coordination environment can be adjusted, thus regulating the type and quantity of active species. Together with its abundant active sites and appropriate pore size, the optimized Cu1Zn2-BMO not only achieves a high activity (98% yield) for the coupling of CO2 and epichlorohydrin under solvent-free mild conditions, but also promotes the N-formylation of CO2 with amines. Worthy to note, the decent chemical stability endows Cu1Zn2-BMO with almost unchanged performance even after long exposure to humidity. Our study offers a reliable strategy for the structure regulation of catalysts to enhance practical CO2 catalytic conversion.