Fabrication of NiO–Cu3Mo2O9 Catalyst for Efficient Hydrogen Gas Production via Ammonia Borane Methanolysis

Abstract

Hydrogen production via ammonia borane (AB) methanolysis is a promising strategy for H₂ supply. However, it requires high-performance catalysts that are low-cost and highly stable to efficiently catalyze the hydrogen generation reaction. Herein, we report a novel NiO–Cu3Mo2O9 hierarchical nanocatalyst synthesized via a one-pot hydrothermal–calcination method for catalyzing hydrogen production through AB methanolysis. Systematic characterizations, including XRD, SEM, TEM, XPS, and BET analyses, were conducted to confirm the successful synthesis of NiO–Cu3Mo2O9. The catalyst exhibited a low activation energy (Ea = 18.9 kJ·mol⁻¹), excellent stability (H₂ production rate = 170 mL H2·min⁻¹; retaining > 90% of its initial activity after 6th cycle), and a high turnover frequency (TOF) of 49.8 min⁻¹. Furthermore, the NiO–Cu3Mo2O9 catalyst demonstrated a synergistic effect, achieving a hydrogen generation rate (HGR) of 1,200 mL H2·g− 1·min− 1, compared with the Cu3Mo2O9 catalyst (HGR = 360 mL H2·g− 1·min− 1). In addition, kinetic studies of AB methanolysis revealed that the reaction was temperature-dependent, with an optimum temperature of 30 °C (303 K). The catalytic reaction rate showed a positive correlation with both the AB dosage and the catalyst loading