A silica-supported Ni-based catalyst prepared using TEPA for the plasma synthesis of ammonia

Abstract

Ammonia is a potential hydrogen carrier and can be used as an alternative fuel. In this study, plasma cooperative catalytic synthesis ammonia was used. The catalyst consisted of Ni impregnated into silica, using one of three complexing agents (TEPA, EDTA and GLY) and compared with conventional impregnation methods. The unsaturated coordinated Ni(tepa)2+ will coordinate with the hydroxyl groups on the silica surface. When using the catalyst prepared by TEPA, the ammonia synthesis rate was 3.8 times higher than with no catalyst, and 1.4 times higher than the catalyst made by conventional impregnation method. XRD and TEM show that the catalyst prepared using TEPA exhibited the smaller metal particle size, the higher dispersion and the stronger interaction between metal and support than other catalysts. XPS indicate that the good metal dispersion of the catalyst facilitate form more Ni3N during the reaction, which will greatly improve the activity of the catalyst.