Au/Pt Bimetallic Nanowires with Stepped Pt Sites for Enhanced C-C Cleavage in C2+ Alcohol Electro-oxidation Reactions

Kecheng Wei; Honghong Lin; Xueru Zhao; Zhonglong Zhao; Nebojsa Marinkovic; Michael Morales; Zhennan Huang; Laura Perlmutter; Huanqin Guan; Cooro Harris; Miaofang Chi; Gang Lu; Kotaro Sasaki; Shouheng Sun

doi:10.1021/jacs.3c07027

Au/Pt Bimetallic Nanowires with Stepped Pt Sites for Enhanced C-C Cleavage in C2+ Alcohol Electro-oxidation Reactions

J Am Chem Soc. 2023 Aug 30;145(34):19076-19085. doi: 10.1021/jacs.3c07027. Epub 2023 Aug 22.

Authors

Affiliations

¹ Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States.
² Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States.
³ School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China.
⁴ Department of Chemical Engineering, Columbia University, New York, New York 10027, United States.
⁵ Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
⁶ Department of Physics and Astronomy, California State University Northridge, Northridge, California 91330, United States.

PMID: 37606196
DOI: 10.1021/jacs.3c07027

Abstract

Efficient C-C bond cleavage and oxidation of alcohols to CO₂ is the key to developing highly efficient alcohol fuel cells for renewable energy applications. In this work, we report the synthesis of core/shell Au/Pt nanowires (NWs) with stepped Pt clusters deposited along the ultrathin (2.3 nm) stepped Au NWs as an active catalyst to effectively oxidize alcohols to CO₂. The catalytic oxidation reaction is dependent on the Au/Pt ratios, and the Au_1.0/Pt_0.2 NWs have the largest percentage (∼75%) of stepped Au/Pt sites and show the highest activity for ethanol electro-oxidation, reaching an unprecedented 196.9 A/mg_Pt (32.5 A/mg_Pt+Au). This NW catalyst is also active in catalyzing the oxidation of other primary alcohols, such as methanol, n-propanol, and ethylene glycol. In situ X-ray absorption spectroscopy and infrared spectroscopy are used to characterize the catalyst structure and to identify key reaction intermediates, providing concrete evidence that the synergy between the low-coordinated Pt sites and the stepped Au NWs is essential to catalyze the alcohol oxidation reaction, which is further supported by DFT calculations that the C-C bond cleavage is indeed enhanced on the undercoordinated Pt-Au surface. Our study provides important evidence that a core/shell structure with stepped core/shell sites is essential to enhance electrochemical oxidation of alcohols and will also be central to understanding electro-oxidation reactions and to the future development of highly efficient direct alcohol fuel cells for renewable energy applications.