Hydrogenation of CO2 to higher alcohols on an efficient Cr-modified CuFe catalyst

CO2 hydrogenation to higher alcohols (C2+OH) is a promising approach to achieve carbon recycling, but it is a challenge due to complex reaction network. Herein, various Cr-modified CuFe (Cr(x)-CuFe) catalysts were prepared, and their catalytic performance and reaction mechanism in CO2 hydrogenation to C2+OH were investigated. Introduction of small amounts of Cr enhances the interaction between Cu and Fe species, which alleviates CO over-dissociation and inhibits generation of iron carbides. In contrast, more acetate and acetal-dehyde intermediates are produced via promoting the reaction of CHx with non-dissociated CO. Cr(1%)-CuFe showed CO2 conversion, C2+OH selectivity and space-time yield (STY) as high as 38.4%, and 29.2% and 104.1 mg gcat  1 h  1, at 320 degrees C, 4.0 MPa and GHSV of 6000 mL gcat 1 h  1. Interestingly, C2+OH STY was further elevated to 268.5 mg gcat  1 h  1, with a catalytic lifetime of at least 120 h, when GHSV was increased to 48000 mL gcat  1 h  1.

Automated summary

In this study, various Cr-modified CuFe catalysts were prepared and their catalytic performance and reaction mechanism in CO2 hydrogenation to C2+OH were investigated. The introduction of small amounts of Cr enhanced the interaction between Cu and Fe species, alleviating CO over-dissociation and inhibiting the generation of iron carbides. The Cr(1%)-CuFe catalyst exhibited high CO2 conversion, C2+OH selectivity, and space-time yield (STY).