Transition metal nanoparticles supported La-promoted MgO as catalysts for hydrogen production via catalytic decomposition of ammonia

The uniformly dispersed transition metal (Co, Ni and Fe) nanoparticles supported on the surface of La-promoted MgO were prepared via a deposition-precipitation method for hydrogen production from catalytic decomposition of ammonia. X-ray diffraction, N-2 adsorption-desorption, transmission electron microscopy, temperature-programmed reduction and temperature-programmed desorption were used to investigate the structure-activity relation of catalysts in NH3 decomposition. The results show that the strong interaction between active species and support can effectively prevent the active species from agglomerating during ammonia decomposition reaction. In addition, the introduction of La species not only facilitates the adsorption and decomposition of NH3 and desorption of N-2, but also benefits the better dispersion of the active species. The prepared catalysts showed very high catalytic activity for ammonia decomposition compared with the same active composition samples that reported previously. Meanwhile, the catalysts showed excellent high-temperature stability and no any deactivation was observed, which are very promising candidates for the decomposition of ammonia to hydrogen. (C) 2019 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.