The oriented conversion of CO2 into target high-value chemicals is an effective way to reduce carbon emissions, but still presents a challenge. In this communication, we report the oriented conversion of CO2 into value-added aromatics, especially para-xylene, in a single pass by combining core-shell structured Zn-doped H-ZSM-5 (Zn-ZSM-5@SiO2 ) and a Cr2 O3 component. Through precise regulation of the acidity of Zn-ZSM-5@SiO2 , high para-xylene selectivity (38.7 % in the total products) at a CO2 conversion of 22.1 % was achieved. Furthermore, a CO2 -assisted effect in the synthesis of aromatics during the tandem process has been clarified through a control experiment. The CO2 reactant can act as a hydrogen acceptor to accelerate the dehydrogenation of alkenes, intermediates in the synthesis of aromatics, thereby increasing the driving force towards aromatics in the tandem reaction process.
Keywords: CO2 conversion; bifunctional catalysts; green chemistry; xylenes; zeolites.
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