One-pass selective conversion of syngas to para-xylene†
The finite petroleum resources and environmental crisis compel the development of non-petroleum carbon resources by chemical transformation routes. Syngas (CO + H2) is a crucial junction point that exclusively bridges the non-petroleum carbon resources and other basic chemicals like alcohols, alkane/alkenes, etc. However, the one-pass conversion of syngas to value-added aromatics, especially para-xylene, is still a big challenge. Here we presented a promising hybrid catalyst, named Cr/Zn–Zn/Z5@S1, to effectively realize the one-pass conversion of syngas to para-xylene. This hybrid catalyst exhibited enhanced activity on syngas conversion (CO conversion of 55.0%), good stability of catalyst lifetime and considerable selectivity of para-xylene (27.6% in the total products and 77.3% in xylene). The characterization and catalytic performance evaluation revealed that the well-designed core–shell Zn/Z5@S1 zeolite, as a vital part of this Cr/Zn–Zn/Z5@S1 hybrid catalyst, substantially contributed to its extreme performance for the para-xylene one-pass precise synthesis from syngas. The concerted combination of two components in this hybrid catalyst can effectively depress the formation of unwanted by-products and facilitate the oriented synthesis of para-xylene from syngas with unprecedented efficiency at the same time.