Small-sized HZSM-5 zeolite as highly active catalyst for gas phase dehydration of glycerol to acrolein

• Published in: Journal of catalysis 2010, Vol.269 (1), p.71-79
• Main Authors: Jia, Chun-Jiang, Liu, Yong, Schmidt, Wolfgang, Lu, An-Hui, Schüth, Ferdi
• Format: Article
• Language: English
• Subjects: Acrolein; Catalysis; Catalysts; Chemistry; Dehydration; Exact sciences and technology; Gases; General and physical chemistry; Glycerol dehydration; HZSM-5; Ion-exchange; Minerals; Particle size; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Zeolite; Zeolites: preparations and properties
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2009.10.017

The catalytic behavior of nanocrystalline HZSM-5 catalyst with a Si/Al ratio of 65 was studied in the gas phase dehydration of aqueous glycerol. Compared with bulk HZSM-5, the small-sized catalyst exhibits greatly enhanced catalytic performance in glycerol dehydration even at very high GHSV = 1438 h −1. The catalytic properties of nanocrystalline HZSM-5 catalysts with high Si/Al molar ratio (ca. 65) were investigated in the gas phase dehydration of aqueous glycerol. Compared with bulk HZSM-5, the small-sized catalyst exhibits greatly enhanced catalytic performance in glycerol dehydration even with very high GHSV (=1438 h −1). Catalysts with different Si/Al ratios were studied, but it is difficult to separate the influence of Si/Al ratio from that of particle size. However, by varying the proton exchange degree for one mother batch of zeolite, a series of H x Na 1 –x ZSM-5 catalysts with same particle size and different Brønsted acid site densities was prepared. The catalytic results for this series of samples show that high density of Brønsted acid sites favors the production of acrolein. Based on these results, small-sized HZSM-5 with high aluminum content appears to be most promising for gas phase dehydration of glycerol.