Construction of an electron-transfer channel Cu-O-Ni to inhibit the overoxidation of Ni for durable methanol oxidation at industrial current density

• Published in: Chemical science (Cambridge) 2024-07, Vol.15 (28), p.1113-112
• Main Authors: Tian, Han, Wang, Xiaohan, Luo, Wenshu, Ma, Rundong, Yu, Xu, Li, Shujing, Kong, Fantao, Cui, Xiangzhi, Shi, Jianlin
• Format: Article
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d4sc00842a

The electrocatalytic methanol oxidation reaction (MOR) is a viable approach for realizing high value-added formate transformation from biomass byproducts. However, usually it is restricted by the excess adsorption of intermediates (CO ad ) and overoxidation of catalysts, which results in low product selectivity and inactivation of the active sites. Herein, a novel Cu-O-Ni electron-transfer channel was constructed by loading NiCuO x on nickel foam (NF) to inhibit the overoxidation of Ni and enhance the formate selectivity of the MOR. The optimized NiCuO x -2/NF demonstrated excellent MOR catalytic performance at industrial current density ( E 500 = 1.42 V) and high faradaic efficiency of ∼100%, as well as durable formate generation up to 600 h at ∼500 mA cm −2 . The directional electron transfer from Cu to Ni and enhanced lattice stability could alleviate the overoxidation of Ni( iii ) active sites to guarantee reversible Ni( ii )/Ni( iii ) cycles and endow NiCuO x -2/NF with high stability under increased current density, respectively. An established electrolytic cell created by coupling the MOR with the hydrogen evolution reaction could produce H 2 with low electric consumption (230 mV lower voltage at 400 mA cm −2 ) and concurrently generated the high value-added product of formate at the anode. A novel Cu-O-Ni channel with electron transfer from Cu to Ni was constructed to inhibit the overoxidation of Ni 3+ and guarantee reversible Ni 2+ /Ni 3+ cycling, which led to high methanol oxidation activity at elevated current density.