Alkaline titanium carbide (MXene) engineering ultrafine non-noble nanocatalysts toward remarkably boosting hydrogen evolution from ammonia borane hydrolysis

Abstract

The rational design of cost-effective and stable heterogeneous nanocatalysts with high activities is vital yet challenged for utilization of sustainable hydrogen fuel. Herein, we report a novel surficial alkaline functional strategy for immobilization of non-noble CuCo nanoparticles (NPs) on diamine-alkalized-functionalized Ti₃C₂ surfaces (CuCo/PDA-Ti₃C₂). By virtue of coordination effect, ultrafine CuCo NPs with the size of 1.8 nm were well dispersed on Ti₃C₂ surface. Strikingly, the optimized CuCo/PDA-Ti₃C₂ nanocatalyst presents an impressive catalytic performance toward ammonia borane hydrolysis (ABH) without any additive, with a completed conversion and a high turnover frequency (TOF) value of 71.8 mol_H2mol_cat^-1min^-1 at mild condition. The alkaline amine groups induced a strong support-metal synergistic interaction (SMSI) to not only regulate the localized charge distribution and electron energy levels near active sites, but also optimize the surface d center and adsorption/desorption behavior, resulting in an accelerating O-H bond cleavage in water molecular. This work presents a novel and universal strategy for developing alkaline titanium carbide (MXene)-based heterogeneous nanocatalysts for hydrogen energy society.