RuCo@P Core-Shell Nanoparticles Filled with Carbon Nanotubes for Highly Effective Catalytic Hydrolysis of Ammonia Borane

Abstract

The doping of nonmetals in multiphase metal catalysts can effectively improve the catalytic performance and reduce the catalyst cost. In this study, we synthesized transition metal phosphide (RuCo@P/CNT) catalysts loaded on carbon nanotubes (CNT) using sodium borohydride (NaBH4) as the reducing agent. The microstructure and phase composition of RuCo@P/CNT nanoparticles were investigated using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and BET. RuCo@P/CNT nanoparticles show superior catalytic activity and cycle stability in the catalytic ammonia borane hydrolysis process compared to Ru/CNT and RuCo/CNT nanoparticles, retaining 65.74% of their initial catalytic activity after 5 reaction cycles. The test yielded values for turnover frequency and activation energy of 327.33 min-1 and 36.77 kJ·mol-1, respectively. Additionally, a kinetic isotope effect value of 2.61 for H2O/D2O showed that O-H bond breaking in proportional acceptor water is the decisive step in the dehydrogenation of ammonia borane, and based on this discovery, a specific mechanism for the catalytic hydrolysis of AB by RuCo@P NPs is postulated.