Study on the kinetic enhancement of MgH2 accelerated by nanorod-shaped Ni/NiO heterojunction catalyst

Due to the slow hydrogen release kinetics and high hydrogen release temperature, the application of MgH 2 is subject to many restrictions. In this paper, a rod-shaped catalyst assembled from Ni/NiO nanoparticles was synthesized. During the hydrogen release process, the interfacial reaction induces the in-situ generation of Mg 2 Ni, thereby providing a rapid hydrogen transport channel. Compared with pure Ni catalysts, the Ni/NiO heterojunction can reduce the initial desorption temperature, the peak desorption temperature, and the complete hydrogen release temperature of MgH 2 to 191 °C, 259 °C, and 275 °C, respectively. In addition, the reversible hydrogen storage performance, it shows an initial capacity of 6.38 wt%, and the capacity retention rate after 20 cycles is 94.12%. Kinetic analysis indicated that the activation energy of dehydrogenation was reduced to 93.78 kJ mol −1 , confirming that the synergistic effect of the Ni/NiO heterointerface and Mg 2 Ni generation jointly accelerated the hydrogen release kinetics. Download: Download high-res image (195KB) Download: Download full-size image The rod-shaped catalyst assembled from Ni/NiO nanoparticles significantly enhanced the hydrogen release performance and cycling stability of MgH 2 .