Substrate-induced redox reconstruction of nickel sites in organic oxidation electrocatalysis

Organic oxidation reactions (OORs) are emerging as attractive alternatives to the oxygen evolution reaction (OER) for renewable energy conversion. Effective OOR demands catalysts that function across diverse organic substrates and a broad chemical phase space. Here, we report a well-defined Ni 12 P 5 nanostructure as an efficient alkaline OOR catalyst for 5-hydroxymethylfurfural (HMF) and 5-amino-1H-tetrazole (AmTET), yielding carboxylated and dehydrogenative N=N-coupled products, respectively. Dynamic redox behavior and self-reconstruction were investigated to identify the active phase. At OER potentials, Ni 12 P 5 converts into Ni III/IV oxyhydroxides typical of OER catalysts. However, upon introducing organic substrates at catalytic potentials, the in situ formed Ni III/IV OOH is rapidly reduced, generating an OOR-active material dominated by Ni II sites, as evidenced by quasi in situ X-ray absorption and in situ Raman spectroscopy. This work demonstrates the versatility and robustness of Ni-based electrocatalysts formed via potential-driven material transformations.