One-pot synthesis of mesoporous Cu-SiO2-Al2O3 bifunctional catalysts for hydrogen production by dimethyl ether steam reforming

Abstract

Mesoporous Cu-SiO2-Al2O3 bifunctional catalysts with highly dispersed active sites and increased acid amount were synthesized via a modified evaporation induced self-assembled (EISA) method and firstly used for dimethyl ether steam reforming (DME SR). Various techniques including XRD, nitrogen adsorption-desorption, N2O chemisorption, H2-TPR, NH3-TPD, TEM, FT-IR and 27Al MAS NMR were employed to characterize the prepared catalysts. The Cu-SiO2-Al2O3 catalyst calcinated at 700°C with 7.5% Cu and 17.5% Si exhibited the highest DME conversion rate up to 100% and H2 yield of 90%, and good reaction-regeneration performance. The long-range ordered mesoporous structure, improved specific surface area and pore volume, and highly dispersion of Cu and CuAl2O4 nanopaticles were obtained after the incorporation of SiO2, which were found to be influential to the enhanced catalytic performance. Notably, the added SiO2 helped to form Lewis acid, leading to a huge increase in solid acid amount, which further improved the DME hydrolysis activity.