Identification and Origination of the O*-Dominated β-NiOOH Intermediates with High Intrinsic Activity for Electrocatalytic Alcohol Oxidation
Qingyu Xue, Zhaoming Xia, Wangyan Gou, Jun Bu, Jiayuan Li, Hai Xiao, Yongquan Qu
Abstract
Ni-based electrocatalysts for alcohol oxidation offer a cost-effective route for energy/chemical conversion, and yet are limited by their low activity. Dominant OH* and few O* species on in situ formed electroactive β-NiOOH of Ni-based electrodes are identified as the catalytic intermediates. We theoretically profile that OH*-dominated β-NiOOH intrinsically has low reactivity toward the α-C–H of alcohols, limiting their activation/dissociation. Whereas, O*-dominated β-NiOOH has high reactivity, enabling stronger α-C–H activation/dissociation. Combined with operando characterizations, phytate enabled the construction of an O*-dominated β-NiOOH surface on Ni foam during operation, leading to a 10.2-fold enhancement of activity for benzyl alcohol electrooxidation.