Constructing Lewis Acid–Base Pairs to Boost Electrocatalytic Hydrogenation of p‐Nitrobenzoic Acid to Valuable p‐Aminobenzoic Acid Using Water as the Hydrogen Source

Abstract 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 Co_1‐xNi_x(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 ‐0.545 V (vs reversible hydrogen electrode, RHE) under 0.1 m phosphate buffered solution (PBS) neutral electrolyte. Besides, it can maintain a high electrocatalytic activity for at least eight electrocatalytic cycle‐test.