Tandem catalysts composed of different morphology HZSM-5 and metal oxides for CO2 hydrogenation to aromatics

The efficient that to concert CO2 into high value-added chemicals is a promising and potential strategy to reduce the consumption of petroleum resources, especially as an alternative route to MTA, where direct conversion of aromatics can be achieved through CO2 hydrogenation. Herein, a series of metal oxides (In2O3, Cu-Zn-Al and ZnZrxO with different Zr/Zn and calcined at different temperatures) and different morphologies of spherical, hollow, sheet, and chain HZSM-5 were rationally designed, and then connected with metal oxides and HZSM-5 in tandem to investigate the reaction conditions and catalytic performance for the direct conversion that from CO2 hydrogenation to aromatics, the reaction mechanism was investigated using In-situ DRIFTS. Furthermore, due to the synergy between the respective excellent properties of HZSM-5 zeolites and metal oxides, the selectivity of aromatic up to 75.7% and conversion of CO2 was 14.5% over ZnZr7O(5 0 0)-sheet HZSM-5 tandem catalyst, while achieving high selectivity of 64.1% for BTX. Moreover, high selectivity of the target product to xylene was achieved over the ZnZr7O(5 0 0)-chain HZSM-5 tandem catalyst due to the fact that the molecular kinetic radius of p-xylene was close to the b-axis pore radius of HZSM-5, and an appropriate increase in the b-axis length was beneficial to improve the selectivity of p-xylene, which opened up a broad path for the design of catalysts for CO2 hydrogenation to aromatics.