Selective conversion of CO<sub>2</sub> and H<sub>2</sub> into aromatics.

Ni, Youming; Chen, Zhiyang; Fu, Yi; Liu, Yong; Zhu, Wenliang; Liu, Zhongmin · Nat Commun · 2018

basic_science · Level V

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Abstract

Transformation of greenhouse gas CO<sub>2</sub> and renewable H<sub>2</sub> into fuels and commodity chemicals is recognized as a promising route to store fluctuating renewable energy. Although several C<sub>1</sub> chemicals, olefins, and gasoline have been successfully synthesized by CO<sub>2</sub> hydrogenation, selective conversion of CO<sub>2</sub> and H<sub>2</sub> into aromatics is still challenging due to the high unsaturation degree and complex structures of aromatics. Here we report a composite catalyst of ZnAlO<sub>x</sub> and H-ZSM-5 which yields high aromatics selectivity (73.9%) with extremely low CH<sub>4</sub> selectivity (0.4%) among the carbon products without CO. Methanol and dimethyl ether, which are synthesized by hydrogenation of formate species formed on ZnAlO<sub>x</sub> surface, are transmitted to H-ZSM-5 and subsequently converted into olefins and finally aromatics. Furthermore, 58.1% p-xylene in xylenes is achieved over the composite catalyst containing Si-H-ZSM-5. ZnAlO<sub>x</sub>&H-ZSM-5 suggests a promising application in manufacturing aromatics from CO<sub>2</sub> and H<sub>2</sub>.