Enhanced aromatic selectivity by the sheet-like ZSM-5 in syngas conversion

Aromatics are important basic chemicals. However, direct conversion of syngas via the conventional Fischer-Tropsch synthesis produces little aromatics. We presented herein that a bifunctional composite of ZSM-5 in combination with ZnCrOx catalyzes syngas conversion to aromatics. Particularly, ZSM-5 crystals with a sheet-like morphology can enhance significantly the aromatization activity. The lower length ratio of the b/a axes of the crystals, the more aromatics form but without influencing the selectivity of small molecules such as CH4 and C-2-C-4. Since the acid properties and the Al chemical environment were not altered while the morphology changed, the enhanced aromatic selectivity is likely attributed to the favored diffusion of aromatics in these sheet-like crystals. (C) 2018 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.