The influence of the compositions and structures of Cu-ZrO2 catalysts on the catalytic performance of CO2 hydrogenation to CH3OH

Abstract

In this paper, Cu-ZrO2 catalysts were prepared and used for CH3OH synthesis through CO2 hydrogenation to clarify the influence of their compositions and structures on the catalytic performance. We mainly address the problem that how the oxygen vacancy and Cu-ZrO2 interface affect the catalytic performance jointly, because the previous articles only pay attention to the influence of the interface on CH3OH synthesis. Combined with experiments and various structural characterizations, we propose that oxygen vacancies play an essential role in CO2 activation instead of the interface; CH3OH selectivity is determined by the low-valence Cu species (Cu0 and Cu+) and ZrO2 interface (the main factor), and the pore size. The in-situ DRIFTS demonstrates that the conversion of *HCOO active intermediates to *CH3O on the optimal catalyst (CuZr-1) is faster. DFT calculations also shed light on the importance of oxygen vacancy in CO2 adsorption and the formate pathway. We believe this work provides useful insight for researchers to design highly efficient Cu-based catalysts for CO2 hydrogenation to CH3OH.