Product Ligand-Modification on Ni(OH)₂ for Boosted Electrocatalytic Oxidation of Aromatic Alcohols

The development of active electrocatalysts for converting biomass-derived aromatic alcohols into value-added acids is of great significance. Ni(OH)₂ has been employed as a cost-effective catalyst, unfortunately, suffering from rather low catalytic activity due to the considerable energy barrier to transform into active NiOOH and the weak interaction with reactants. To address these limitations, a novel “product ligand-modification” (PLM) strategy has been proposed here simply by adopting the target molecule ligands as modification units, which simultaneously facilitates the Ni(II)/Ni(III) redox kinetics and significantly enriches reactants at the catalytic surface via profound π-π stacking interaction. The PLM strategy has been demonstrated to exhibit exceptionally high performance in electro-oxidizing aromatic alcohols into corresponding acids across various product ligand-Ni(OH)₂ (PL-Ni(OH)₂) catalysts. As a typical paradigm, the aromatic ligand FDCA-modified Ni(OH)₂ catalyst (termed FDCA-Ni(OH)₂) demonstrates significantly enhanced BHMF electrocatalytic oxidation activity, featuring a BHMF conversion rate of >99.4%, FDCA selectivity and yield of 99.2% and 98.6%, and Faradaic efficiency of 99.0%. Furthermore, FDCA-Ni(OH)₂ features an excellent stability for over 250 h in a flow electrolyzer to produce FDCA with a >99.0% purity. This PLM strategy offers valuable insights into the performance enhancement of Ni(OH)₂ catalyst for the targeted conversion of aromatic reactants.