Reforming Methane with CO2over Hierarchical Porous Silica-Supported Nickel Catalysts Modified with Lanthanum Oxide

Abstract

Hierarchical porous silica-supported nickel catalysts modified with different amounts of lanthanum (La) were synthesized via "one-pot"method using cetyltrimethylammonium bromide as template, urea as precipitant, and tetraethyl orthosilicate as silica source. Their catalytic performances were evaluated in dry reforming with methane under different conditions (La loading, reaction temperature, and time on stream). The synthesized and spent catalysts were extensively characterized by ICP, physisorption, chemisorption, XRD, TPR, XPS, HAADF-TEM, TPH, Raman's spectroscopy, and TG analysis. The impact of lanthanum amount on the catalytic performance, sintering, and carbon deposition was discussed. Compared to unmodified catalyst, La promoter induced the nickel nanoparticles with larger crystallite sizes and weakened the metal-support interaction as well as the formation of 1: 1 nickel-phyllosilicate, leading to the metal sintering increasing in the order Ni1.5La/SiO2