CO2 hydrogenation to dimethyl ether over CuO–ZnO–Al2O3/HZSM-5 prepared by combustion route

Abstract

CuO–ZnO–Al₂O₃/HZSM-5 catalysts were prepared and characterized by XRD, BET, N₂O titration, H₂-TPR, FESEM and NH₃-TPD techniques. CuO–ZnO–Al₂O₃ catalysts were obtained by a simple and fast urea–nitrate combustion method and then mixed physically with HZSM-5 to perform one step synthesis of dimethyl ether (DME) from carbon dioxide (CO₂) hydrogenation. The results showed that the grain size and copper surface areas of the catalysts were highly affected by the amount of urea in the preparation, and their catalytic performances were consequently influenced. A CO₂ conversion of 30.6% and DME yield of 15% over the optimal catalyst were obtained by controlling the molar ratio of urea to metal nitrate. The work will benefit the rational design of new catalysts suitable for CO₂ utilization.