High selectivity production of light aromatics via CO hydrogenation by tuning the crystal size of plate-like zeolite.

Direct hydrogenation of CO to high-value chemicals, especially aromatics, is an effective strategy for the alleviation of carbon emissions. Tremendous progress has been made in the direct conversion of CO into aromatics recently, but the highly selective synthesis of light aromatics (C-C) remains a huge challenge due to the complex role of Brønsted acid sites (BAS) and pore properties of zeolite in aromatic synthesis. Herein, a combination of the Na-modified ZnFeO and plate-like ZSM-5 (pZ5) with different b-axis thicknesses, which shows excellent performance for CO hydrogenation to light aromatics. The maximum of light aromatic selectivity was up to 73.4 % in total aromatics at 33.1 % CO conversion. Additionally, the selectivity towards CO and CH is 5.5 % and 13.5 % over this catalyst system. Multiple characterizations illustrate that the suitable amount of the residual sodium, tuning the crystal size of pZ5 zeolite along the a- and b-axis and regulating the distribution of BAS in pZ5 zeolite can significantly improve the light aromatic selectivity.