La(OH)3-decorated NiFe nanoparticles as efficient catalyst for hydrogen evolution from hydrous hydrazine and hydrazine borane

Abstract

Ultrafine NiFe nanoparticles (NPs) decorated by La(OH)3 have been successfully prepared via a facile one-step co-reduction method without the help of surfactant or support. It was found that after being decorated with La(OH)3, the NiFe–La(OH)3 NPs have a smaller particle size and lower crystallinity. The resultant NiFe–La(OH)3 nanocatalyst exhibits an excellent catalytic activity, 100% H2 selectivity, and satisfied recyclability for hydrogen evolution from hydrous hydrazine (N2H4·H2O) at 343 K under alkaline conditions, giving a high turnover frequency (TOF) value of 100.6 h−1, which is more than 35 times higher than pure NiFe NPs (2.8 h−1). The kinetics study shows that with respect to the concentration of catalyst and N2H4, the N2H4 dehydrogenation reaction follows fist-order kinetics and zero-order kinetics, respectively. Furthermore, NiFe–La(OH)3 also exhibits an outstanding performance and excellent recycle stability during high dehydrogenation of hydrazine borane (N2H4BH3). The excellent performances for the dehydrogenation of N2H4 and N2H4BH3 could be attributed to the strong interaction between La(OH)3 and NiFe NPs, as well as ultrafine and low crystalline NiFe NPs due to the addition of La(OH)3.