Thermocatalytic decomposition of methane over mesoporous Ni/xMgO·Al_2O_3 nanocatalysts

摘要

This paper describes a facile method to produce mesoporous nanostructure Ni/Al2O3, Ni/MgO, and Ni/xMgO.Al2O3(x: MgO/Al2O3molar ratio) catalysts prepared by “one-pot” evaporation-induced self-assembly (EISA) method with some modifications for investigating in the thermocatalytic decomposition of methane. Detailed characterizations of the material were performed with X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and N2adsorption/desorption, hydrogen temperature-programmed reduction (H2-TPR), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and temperature-programmed oxidation (TPO). The characterizations demonstrated that the synthesized catalysts with various MgO/Al2O3molar ratios possessed mesoporous structure with the high BET area in the range of 216.79 to 31.74 m2 g−1. The effect of different surfactants and calcination temperatures on the characterizations and catalytic activity of the catalysts were also examined in details. The experimental results showed that the catalysts exhibited high catalytic potential in this process and the 55 wt.% Ni/2 MgO·Al2O3catalyst calcined at 600οC possessed an acceptable methane conversion (∼60%) under the harsh reaction conditions (GHSV = 48000 (mL h−1 gcat−1)).