Modulating Ni-O-V Bridges in NiV-Layered Double Hydroxides Microspheres for Robust Electrocatalytic Coupling of...

The co-electrolysis system that couples anodic oxidation of biomass-derived polyols with cathodic nitrate reduction reaction (NO₃RR) represents a promising strategy for biomass valorization and treatment of high-salinity wastewater. Here, we synthesize thin NiV-layered double hydroxides (NiV-LDHs) microspheres featuring engineered Ni-O-V bridge structures as dual-channel electrocatalysts. The newly constructed Ni-O-V bridges confirmed by x-ray absorption spectroscopy effectively modulate the electronic structures of both Ni and V sites. This synergistic enhancement boosts the performance of both anodic 1,5-pentanediol electrooxidation to produce glutaric acid (GA) and NO₃RR to ammonia. The NiV-LDHs anode enables electrolysis at a low cell voltage of 1.5 V versus RHE, exhibiting a GA Faradaic efficiency of 98.5% and a high GA yield of 2.56 mmol h^-1 cm^-2. Operando studies and density functional theory reveal that the strong electronic coupling within NiV-LDHs optimizes the competitive adsorption between 1,5-pentanediol and OH* on the catalyst surface. Moreover, the NiV-LDHs cathode exhibits outstanding NO₃RR performance, achieving a high ammonia yield of 2.28 mmol h^-1 cm^-2 with a Faradaic efficiency of 96.1%, surpassing most reported electrocatalysts. A continuous paired electrolysis operation over 240 h successfully produced GA (55.98 g) and NH₄Cl (23.48 g) powders, demonstrating great potential for industrial application.