(344d) Roles of Interaction between Components in CuO-ZnO-ZrO2-Al2O3/HZSM-5 Bifunctional Catalysts for Direct Synthesis of Dimethyl Ether Via CO2 Hydrogenation

Catalytic hydrogenation of CO₂ to dimethyl ether (DME) has received lots of interests, since DME not only can be used as a promising intermediate for high value-added chemicals, but also an alternative fuel owing to its high cetane number (55-60), low auto-ignition temperature, and considerable reduction of CO and NO_x in the exhaust gases. Recently, a lot of research focused on bifunctional catalyst for one-step DME synthesis via CO₂ hydrogenation. In this study, the roles of interaction in the CuO-ZnO-ZrO₂-Al₂O₃ (CZZA)/HZSM-5 bifunctional catalysts between two catalyst components on the catalytic activity and deactivation behavior for DME synthesis via CO₂ hydrogenation were systematically investigated. We found that CZZA catalyst showed excellent stability during methanol synthesis, however, there was severe deactivation in the CZZA/HZSM-5 bifunctional catalysts. The changes of catalyst properties were evaluated by characterizing the fresh and used samples via XRD, TGA, BET and N₂O-chemisorption. Our studies show that it is vital to optimize the level of contact intimacy between two components in the development of bifunctional catalyst for DME synthesis, in order to realize high activity and good stability.