Fabrication of Mo0.1-Cu0.4Ni0.6Co2O4 catalyst based on dual-doping engineering for fast hydrogen release from ammonia borane methanolysis

Constructing highly active, low-cost catalysts remains a key challenge for the mild, isothermal hydrogen-release pathway of ammonia-borane (AB) methanolysis. In this study, a systematic screen covering monodoping on NiCo 2 O 4 (Cu, W, Br, and Mo) and secondary co-doping on Cu 0.4 Ni 0.6 Co 2 O 4 (with W, Br, and Mo) identifies Mo 0.1 -Cu 0.4 Ni 0.6 Co 2 O 4 as the optimum composition. The Cu/Mo co-doped catalyst achieves a turnover frequency (TOF) of 43.08 mol H 2 mol −1 ·min −1 (approximately 78 times that of pristine NiCo 2 O 4 ) and maintains robust hydrogen-evolution performance over 10 cycles. Based on the experimental results, it is revealed that binary doping regulates the surface electronic states of the Mo 0.1 -Cu 0.4 Ni 0.6 Co 2 O 4 catalysts. Upon introducing Mo into Cu 0.4 Ni 0.6 Co 2 O 4 , electrons shift from Ni to Cu/Co, rendering Ni relatively electron-deficient and Cu/Co electron-enriched. The resulting charge redistribution lowers the activation barriers, accelerates the reaction kinetics, and promotes the methanolysis of AB. In summary, this work establishes dual-doping engineering for modulating charge redistribution as an effective strategy to develop efficient, noble-metal-free, and scalable catalysts towards AB methanolysis for fast hydrogen production.