Effect of steaming on the catalytic performance of ZSM-5 zeolite in the selective oxidation of phenol by nitrous oxide

Autor:	Larisa V. Pirutko, D.P. Ivanov, Gennady I. Panov
Rok vydání:	2014
Předmět:	Catechol Hydroquinone organic chemicals Inorganic chemistry Steaming food and beverages Resorcinol Catalysis chemistry.chemical_compound chemistry Phenol Physical and Theoretical Chemistry Selectivity Brønsted–Lowry acid–base theory
Zdroj:	Journal of Catalysis. 311:424-432
ISSN:	0021-9517
Popis:	Gas-phase oxidation of phenol to dihydroxybenzenes (DHB) with nitrous oxide was performed over a set of ZSM-5 zeolites steamed at different temperatures in the range from 550 to 750 °C. The best of the catalysts demonstrated 70% N 2 O conversion and a more than 90% selectivity for DHB. However, significant differences were observed in DHB isomer distribution and catalyst deactivation due to changes in the acidity of the zeolites. The steaming procedure reduces the concentration of Bronsted acid sites, thus allowing a decrease in coke loading. Simultaneously, a substantial decline in the molar ratio of hydroquinone to catechol in the reaction products was observed, mainly due to the increased selectivity to the ortho isomer – catechol. These results can be used to control the selectivity for different DHB isomers in the title reaction by varying steaming severity.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::56659bd760bc4ebaf80f0bf65195bf79 https://doi.org/10.1016/j.jcat.2013.12.010 Zobrazit plný text záznamu Full Text from ScienceDirect