BTX production by coaromatization of methane and propane over gallium oxide supported on mesoporous HZSM-5

2 wt% GaO_y catalysts supported on mesoporous HZSM-5 and microporous HZSM-5 (denoted as 2GaO_y/meso-HZSM-5 and 2GaO_y/micro-HZSM-5, respectively) were prepared for use in the BTX (benzene, toluene, and xylene) production by coaromatization of methane and propane. It was revealed that 2GaO_y/meso-HZSM-5 catalyst showed higher reactant conversion and initial BTX yield than 2GaO_y/micro-HZSM-5 catalyst due to the enhanced mass transfer through 2GaO_y/meso-HZSM-5 catalyst. On the basis of this result, a series of XGaO_y/meso-HZSM-5 (X = 0.5, 1, 2, 4, and 6) catalysts with different gallium oxide loading (X, wt%) were prepared for BTX production by coaromatization of methane and propane. The effect of gallium oxide loading on the acid properties and catalytic activities of XGaO_y/meso-HZSM-5 catalysts was investigated. It was found that total acidity of the catalysts served as a crucial factor determining the catalytic performance in the BTX production. Conversion of reactants and initial BTX yield increased with increasing total acidity of the catalysts. Among the catalysts tested, 2GaO_y/meso-HZSM-5 catalyst with the largest total acidity showed the best catalytic performance in the BTX production. Thus, an optimal gallium oxide loading of XGaO_y/meso-HZSM-5 catalysts was required for maximum production of BTX by coaromatization of methane and propane.