Efficient hydrogen production from ethanol steam reforming over La-modified ordered mesoporous Ni-based catalysts

Abstract

This paper describes the synthesis of a group of meso-xLaNiAl catalysts with ordered mesostructure and La promoters, and their catalytic performance for hydrogen production from ethanol steam reforming. For comparison, the conventional 0LaNiAl catalyst was prepared by impregnation with γ-Al2O3. The characterization results exhibited that meso-xLaNiAl materials possessed excellent textural properties, such as high specific surface areas, large pore volumes and uniform pore sizes. The ordered mesostructure was beneficial to obtain and maintain the 4–6nm Ni nanoparticles, which were smaller than that of the conventional 0LaNiAl catalyst (∼10nm). Consequently, meso-xLaNiAl catalysts exhibited superior initial activity with respect to the reference 0LaNiAl catalyst, especially at higher temperatures (873 and 973K). Particularly, the meso-3LaNiAl catalyst gained the highest amount of easily reduced Ni species and then the highest active surface areas. In addition, the highest initial activity at 873K is exhibited over meso-3LaNiAl catalyst, which is mainly attributed to the highly dispersed nickel nanoparticles and abundant active surface areas. The meso-3LaNiAl catalyst also exhibited excellent long-term stability. Besides the excellent textural properties, the presence of La-modifiers enhanced the basicity of the catalyst, strengthened the metal-support interaction and cleaned the deposited carbon, resulting in the suppression of carbon deposition and the improvement of stability.