Highly Dispersed Mo Sites on Pd Nanosheets Enable Selective Ethanol-to-Acetate Conversion

Shenglan He; Yue Liu; Hongjian Li; Qianbao Wu; Dongsheng Ma; Daojiang Gao; Jian Bi; Yaoyue Yang; Chunhua Cui

doi:10.1021/acsami.1c01010

Highly Dispersed Mo Sites on Pd Nanosheets Enable Selective Ethanol-to-Acetate Conversion

ACS Appl Mater Interfaces. 2021 Mar 24;13(11):13311-13318. doi: 10.1021/acsami.1c01010. Epub 2021 Mar 9.

Authors

Shenglan He^{1

2}, Yue Liu³, Hongjian Li¹, Qianbao Wu¹, Dongsheng Ma¹, Daojiang Gao², Jian Bi², Yaoyue Yang³, Chunhua Cui¹

Affiliations

¹ Molecular Electrochemistry Laboratory, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China.
² College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, P. R. China.
³ Key Laboratory of Basic Chemistry of the State Ethnic Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, P. R. China.

PMID: 33689263
DOI: 10.1021/acsami.1c01010

Abstract

The fermentation of biomass allows for the generation of major renewable ethanol biofuel that has high energy density favorable for direct alcohol fuel cells in alkaline media. However, selective conversion of ethanol to either CO₂ or acetate remains a great challenge. Especially, the ethanol-to-acetate route usually demonstrates decentoxidation current density relative to the ethanol-to-CO₂ route that contains strongly adsorbed poisons. This makes the total oxidation of ethanol to CO₂ unnecessary. Here, we present a highly active ethanol oxidation electrocatalyst that was prepared by in situ decorating highly dispersed Mo sites on Pd nanosheets (MoO_x/Pd) via a surfactant-free and facile route. We found that ∼2 atom % of Mo on Pd nanosheets increases the current density to 3.8 A mg_Pd^-1, around 2 times more active relative to the undecorated Pd nanosheets, achieving nearly 100% faradic efficiency for the ethanol-to-acetate conversion in an alkaline electrolyte without the generation of detectable CO₂, evidenced by in situ electrochemical infrared spectroscopy, nuclear magnetic resonance, and ion chromatography. The selective and CO₂-free conversion offers a promising strategy through alcohol fuel cells for contributing comparable current density to power electrical equipment while for selective oxidation of biofuels to useful acetate intermediate for the chemical industry.

Keywords: IRAS; biomass; ethanol oxidation; fuel cells; nanosheets.