Aqueous Phase Reforming of ethylene glycol – Role of intermediates in catalyst performance

• Published in: Journal of catalysis 2012-08, Vol.292, p.239-245
• Main Authors: de Vlieger, D.J.M., Mojet, B.L., Lefferts, L., Seshan, K.
• Format: Article
• Language: English
• Subjects: Acetic acid; alkanes; aluminum; aluminum oxide; Antifreeze solutions; Boehmite; byproducts; Catalysis; Catalysts; Chemistry; Deactivation; dehydrogenation; ethanol; Ethylene; ethylene glycol; Exact sciences and technology; FTIR spectroscopy; General and physical chemistry; hydrogen; hydroxylation; methane production; methanol; Raman; Sustainable; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; yields
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2012.05.019

[Display omitted] ► We identified the role of by-products during APR reforming of ethylene glycol on the catalyst efficiency. ► We showed that acetic acid was responsible for deactivation of alumina-supported Pt-based catalysts and discussed the involved mechanism. ► We identified the reason why Ni addition to Pt/Al2O3 catalyst (i) suppressed the formation of alkanes and (ii) extended catalyst lifetime. Liquid product formation during the aqueous catalytic reforming of ethylene glycol (EG) was studied up to 450°C and 250bar pressure. Methanol, ethanol, and acetic acid were the main liquid by-products during EG reforming in the presence of alumina-supported Pt and Pt–Ni catalysts. The effect of these by-products on selectivity and catalyst stability was further investigated by studying reforming of these components. Reforming of these products was shown to be responsible for the formation of alkanes. The high dehydrogenation activity of Pt–Ni catalysts leads to high H2 yields during EG reforming by (i) suppressing the formation of methane during methanol reforming (a major by-product of EG reforming) and (ii) suppressing the formation of acetic acid. In addition, the decrease in acetic acid formation showed a positive effect on catalyst lifetime. Acetic acid was found to be responsible for hydroxylation of the Al2O3 support, leading to migration and coverage of the metal particles by Al(OH)x and resulting in deactivation of the Pt-based catalysts.