Electrocatalytic hydrogenation of toxic nitrobenzene to value-added aniline is of great significance in addressing the issues of energy crisis and environmental pollution. However, it is a considerable challenging and crucial to develop highly efficient and earth-abundant transition metal-based electrocatalysts with superior durability for the electro-hydrogenation of nitrobenzene due to the competitive hydrogen evolution reaction (HER). In this work, a facile approach is designed and introduced to constructing an integrated self-supported heterostructured Co1- xNix(OH)(CO3)/Al(OH)3 nanoarrays (CoNiCH/Al(OH)3) for the electrocatalytic reduction of nitrobenzoic acid (PNBA) to p-aminobenzoic acid (PABA) and its electrocatalytic mechanism for PNBA reduction is investigated. This unique Lewis acid-base pairs with abundant oxygen vacancies (OVs) can effectively regulate the adsorption energy of PNBA and active hydrogen intermediates, facilitate the proton-coupled electrocatalytic reduction process, leading to the high activity and selectivity for PNBA to PABA. The optimal CoNiCH/Al(OH)3-0.5 exhibits outstanding performance for the electrocatalytic hydrogenation of PNBA to PABA with a yield of 92%, selectivity of 95% and Faraday efficiency (FE) of 92% at -0.545V (vs reversible hydrogen electrode, RHE) under 0.1m phosphate buffered solution (PBS) neutral electrolyte. Besides, it can maintain a high electrocatalytic activity for at least eight electrocatalytic cycle-test.
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