Highly Selective Conversion of Carbon Dioxide to Aromatics over Tandem Catalysts

Summary Conversion of CO 2 to aromatics is a promising route to realize the proposal on carbon capture and utilization based on strategic CO 2 carbon resource. In this work, CO 2 is converted to aromatics with aromatics selectivity up to 73% at CO 2 conversion of 14%, and the selectivity of CO was suppressed down to 44% over a tandem catalyst ZnZrO/ZSM-5, which was constructed by using ZnZrO solid solution and H-ZSM-5 zeolite. The selectivity of aromatics can reach to 78% at the space velocity of 1,800 mL/g cat /h. Tandem catalysis enables the direct hydrogenation of CO 2 to aromatics favorable in thermodynamics through the coupling of CO 2 hydrogenation over ZnZrO and aromatics formation over H-ZSM-5. The H 2 O generated through CO 2 hydrogenation over ZnZrO can obviously increase the selectivity of aromatics and the CO 2 in the reaction system promotes the formation of aromatics. Interestingly, it is found that the presence of H 2 O and CO 2 significantly suppresses the generation of polycyclic aromatics and consequently enhances the stability of the tandem catalyst; therefore, no obvious deactivation of tandem catalysts was observed for at least 100 hr in the reaction stream.