Regulating Activity and Selectivity of Photocatalytic CO2 Reduction on Cobalt by Rare Earth Compounds

Yakun Sun; Long Li; Xinxu Li; Ya-Nan Feng; Fei-Fei Chen; Lingyun Li; Yan Yu

doi:10.1021/acsami.2c20402

Regulating Activity and Selectivity of Photocatalytic CO₂ Reduction on Cobalt by Rare Earth Compounds

ACS Appl Mater Interfaces. 2023 Apr 5;15(13):16621-16630. doi: 10.1021/acsami.2c20402. Epub 2023 Mar 22.

Authors

Yakun Sun¹, Long Li¹, Xinxu Li¹, Ya-Nan Feng¹, Fei-Fei Chen¹, Lingyun Li¹, Yan Yu¹

Affiliation

¹ Key Laboratory of Advanced Materials Technologies, International (HongKong Macao and Taiwan) Joint Laboratory on Advanced Materials Technologies, College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, China.

PMID: 36949018
DOI: 10.1021/acsami.2c20402

Abstract

Cobalt-based catalysts are ideal for CO₂ reduction reaction (CO₂RR) due to the strong binding and efficient activation of CO₂ molecules on cobalt. However, cobalt-based catalysts also show low free energy of hydrogen evolution reaction (HER), making HER competitive with CO₂RR. Therefore, how to improve the product selectivity of CO₂RR while maintaining the catalytic efficiency is a great challenge. Here, this work demonstrates the critical roles of the rare earth (RE) compounds (Er₂O₃ and ErF₃) in regulating the activity and selectivity of CO₂RR on cobalt. It is found that the RE compounds not only promote charge transfer but also mediate the reaction paths of CO₂RR and HER. Density functional theory calculations verify that the RE compounds lower the energy barrier of *CO → CO conversion. On the other hand, the RE compounds increase the free energy of HER, which leads to the suppression of HER. As a result, the RE compounds (Er₂O₃ and ErF₃) improve the CO selectivity of cobalt from 48.8 to 69.6%, as well as significantly increase the turnover number by a factor of over 10.

Keywords: CO2 reduction; cobalt; metal−organic frameworks; photocatalysts; rare earth.