In-Situ-Formed Potassium-Modified Nickel-Zinc Carbide Boosts Production of Higher Alcohols beyond CH4 in CO2 Hydrogenation

Ni-based catalysts have been widely studied in the hydrogenation of CO2 to CH4, but selective and efficient synthesis of higher alcohols (C-2+OH) from CO2 hydrogenation over Ni-based catalyst is still challenging due to successive hydrogenation of C1 intermediates leading to methanation. Herein, we report an unprecedented synthesis of C2+OH from CO2 hydrogenation over K-modified Ni-Zn bimetal catalyst with promising activity and selectivity. Systematic experiments (including XRD, in situ spectroscopic characterization) and computational studies reveal the in situ generation of an active K-modified Ni-Zn carbide (K-Ni(3)Zn(1)C(0.)7) by carburization of Zn-incorporated Ni-0, which can significantly enhance CO(2 )adsorption and the surface coverage of alkyl intermediates, and boost the C-C coupling to C2+OH rather than conventional CH4. This work opens a new catalytic avenue toward CO2 hydrogenation to C2+OH, and also provides an insightful example for the rational design of selective and efficient Ni-based catalysts for CO2 hydrogenation to multiple carbon products.

Automated summary

It is challenging to selectively and efficiently synthesize higher alcohols (C2+OH) from CO2 hydrogenation over Ni-based catalysts due to the formation of methanation. In this study, an unprecedented synthesis of C2+OH is achieved by using a K-modified Ni-Zn bimetal catalyst, which exhibits promising activity and selectivity. The in situ generation of an active K-modified Ni-Zn carbide enhances CO2 adsorption and the surface coverage of alkyl intermediates, resulting in the promotion of C-C coupling to C2+OH rather than conventional CH4. This work opens up new possibilities for CO2 hydrogenation to higher alcohols and provides valuable insights for the rational design of selective and efficient Ni-based catalysts.