Enhanced yield of benzene, toulene, and xylene from the co-aromatization of methane and propane over gallium supported on mesoporous ZSM-5 and ZSM-11

[Display omitted] •Mesoporous ZSM-11 and ZSM-5 were prepared by hard-templating method.•Co-aromatization of methane and propane was performed to produce BTX.•Dispersion of Ga species was enhanced with the modification of pore structure.•Gallium supported on mesoporous zeolites exhibited more enhanced BTX yield than conventional zeolites.•Yield of BTX over GaOy/meso-HZSM-11 was higher than that over GaOy/meso-HZSM-5. In this work, mesopore was introduced to ZSM-5 and ZSM-11 to increase the yield of benzene, toluene, and xylene (BTX) from the co-aromatization of methane and propane. Co-aromatization of methane and propane (10:1 M ratio) at 550 °C revealed that gallium oxide (2 wt%) supported on mesoporous zeolites showed higher BTX selectivity and BTX yield than that on microporous zeolites. In particular, the BTX yield of GaOy/meso-HZSM-11 (13.94%) was higher than that of GaOy/meso-HZSM-5 (11.20%), in addition to showing more stable activity up to 6 h. H2-TPR analysis indicated that GaOy/meso-HZSM-11 contains more mobile Ga2O species and GaO+ ion than GaOy/meso-HZSM-5. In addition, NH3-TPD analysis confirmed that such highly dispersed Ga species interact with Brönsted-Lowry acid sites of zeolites to produce medium acid site acting as Lewis acid more abundantly in the former than the latter. In summary, the superior co-aromatization performance with the highest reactant conversion of GaOy/meso-HZSM-11 was achieved by the synergetic effect of Lewis acid site formed by dispersed Ga species and Brönsted-Lowry acid sites of mesoporous HZSM-11.