Key Roles of Interfacial OH- ion Distribution on Proton Coupled Electron Transfer Kinetics Toward Urea Oxidation Reaction

Ruopeng Li; Yaqiang Li; Peixia Yang; Penghui Ren; Dan Wang; Xiangyu Lu; Huiling Zhang; Zhengfeng Zhang; Pengfei Yan; Jinqiu Zhang; Maozhong An; Bo Wang; Huakun Liu; Shixue Dou

doi:10.1002/smll.202302151

Key Roles of Interfacial OH^- ion Distribution on Proton Coupled Electron Transfer Kinetics Toward Urea Oxidation Reaction

Small. 2023 Jul;19(30):e2302151. doi: 10.1002/smll.202302151. Epub 2023 May 16.

Authors

Ruopeng Li¹, Yaqiang Li¹, Peixia Yang¹, Penghui Ren¹, Dan Wang², Xiangyu Lu¹, Huiling Zhang¹, Zhengfeng Zhang³, Pengfei Yan³, Jinqiu Zhang¹, Maozhong An¹, Bo Wang¹, Huakun Liu^{4

5}, Shixue Dou^{4

5}

Affiliations

¹ MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China.
² Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, Jiangsu, 213164, P. R. China.
³ Beijing Key Laboratory of Microstructure and Property of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, P. R. China.
⁴ Institute of Energy Materials Science (IEMS), University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai, 200093, P. R. China.
⁵ Institute for Superconducting & Electronic Materials, Australian Institute of Innovative Materials, University of Wollongong, Wollongong, NSW, 2500, Australia.

PMID: 37191229
DOI: 10.1002/smll.202302151

Abstract

Enhancing alkaline urea oxidation reaction (UOR) activity is essential to upgrade renewable electrolysis systems. As a core step of UOR, proton-coupled electron transfer (PCET) determines the overall performance, and accelerating its kinetic remains a challenge. In this work, a newly raised electrocatalyst of NiCoMoCuO_x H_y with derived multi-metal co-doping (oxy)hydroxide species during electrochemical oxidation states is reported, which ensures considerable alkaline UOR activity (10/500 mA cm^-2 at 1.32/1.52 V vs RHE, respectively). Impressively, comprehensive studies elucidate the correlation between the electrode-electrolyte interfacial microenvironment and the electrocatalytic urea oxidation behavior. Specifically, NiCoMoCuO_x H_y featured with dendritic nanostructure creates a strengthened electric field distribution. This structural factor prompts the local OH^- enrichment in electrical double layer (EDL), so that the dehydrogenative oxidation of the catalyst is directly reinforced to facilitate the subsequent PCET kinetics of nucleophilic urea, resulting in high UOR performance. In practical utilization, NiCoMoCuO_x H_y -driven UOR coupled cathodic hydrogen evolution reaction (HER) and carbon dioxide reduction reaction (CO₂ RR), and harvested high value-added products of H₂ and C₂ H₄ , respectively. This work clarifies a novel mechanism to improve electrocatalytic UOR performance through structure-induced interfacial microenvironment modulation.

Keywords: Nickel-based (oxy)hydroxides; electrode-electrolyte interfacial environments; high-efficiency renewable electrolysis; proton-coupled electron transfers; urea oxidation reactions.

Abstract

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