Catalytic Methylation of Aromatic Hydrocarbons using CO2/H2 over Re/TiO2 and H-MOR Catalysts

A combined catalyst comprising TiO2-supported Re (Re(1)/TiO2; Re=1 wt\%) and H-MOR (SiO2/Al2O3=90) was found to promote the methylation of benzene using CO2 and H2. This catalytic system exhibited high performance with regard to the synthesis of methylated benzenes and gave high yields of total methylated products (up to 52 \% benzene-based yield and 42 \% CO2-based yield) under the reaction conditions employed in this study (pCO2=1 MPa; pH2=5 MPa; T=250 °C; t=20 h) in a batch reactor. Catalyst screening demonstrated that a combination of Re(1)/TiO2 and H-MOR (SiO2/Al2O3=90) exhibited superior performance compared to other combinations of supported metal catalysts and zeolites in terms of both yield and selectivity for methylated benzenes.