Kinetics of catalytic decomposition of hydrous hydrazine over CeO2-supported bimetallic Ni–Pt nanocatalysts

Abstract

Catalytic decomposition of hydrous hydrazine (N2H4·H2O) has been considered as one of the source of hydrogen for fuel cell applications, but the reaction kinetics has received very limited attention. The kinetics of the catalytic decomposition of alkaline N2H4·H2O solutions is investigated over bimetallic Ni–Pt nanocatalysts supported ceria (CeO2), which is prepared by a one-pot co-precipitation method. The resultant Ni–Pt/CeO2 catalyst exhibits high activity and 100% H2 selectivity for the N2H4·H2O decomposition. The catalytic decomposition of N2H4·H2O with respect to N2H4·H2O concentration follows a near-zero-order kinetics at the initial reaction stage with high N2H4·H2O concentrations and the fraction-order kinetics at low N2H4·H2O concentrations. The kinetic rate equation can be expressed as: r = – d[N2H4·H2O]/dt = k[N2H4·H2O]0.52/0.043[NaOH]0.57/0[catalyst]1.03, k = 4.64 × 108 exp(−6591.29/T). Our results provide valuable insights into the catalytic decomposition kinetics of N2H4·H2O.