Ti-doped CeO2 Stabilized Single-Atom Rhodium Catalyst for Selective and Stable CO2 Hydrogenation to Ethanol

Development of effective and stable catalysts for CO2 hydrogenation into ethanol remains a challenge. Herein, we report that Rh-1/CeTiOx single-atom catalyst constructed by embedding monoatomic Rh onto Ti-doped CeO2 support has shown a super high ethanol selectivity (approximate to 99.1 %), record-breaking turnover frequency (493.1 h(-1)), and outstanding stability. Synergistic effects of Ti-doption and monoatomic Rh contribute to this excellent catalytic performance by firstly facilitating oxygen vacancies formation to generate oxygen-vacancy-Rh Lewis-acid-base pairs, which favor CO2 adsorption and activation, cleavage of C-O bonds in CHxOH* and COOH* into CHx* and CO* species, subsequent C-C coupling and hydrogenation into ethanol, and secondly generating strong Rh-O bond by Ti-doping-induced crystal reconstruction, which contributes to striking stability. This work highlights the importance of support elaborating regulation for single-atom catalyst design to substantially improve the catalytic performance.

Automated summary

In this study, a single-atom catalyst consisting of monoatomic Rh embedded onto Ti-doped CeO2 support was developed for CO2 hydrogenation into ethanol. The catalyst exhibited high ethanol selectivity, record-breaking turnover frequency, and outstanding stability. The synergistic effects of Ti-doping and monoatomic Rh contributed to the excellent catalytic performance.