Investigation into chromia-based catalyst and its application in preparing difluoromethane

Autor: Masanori Tamura, Yasuhisa Matsukawa, Heng-dao Quan, Takashi Abe, Akira Sekiya, Junji Mizukado
Rok vydání: 2004
Předmět:
Zdroj: Journal of Molecular Catalysis A: Chemical. 219:79-85
ISSN: 1381-1169
DOI: 10.1016/j.molcata.2004.04.027
Popis: The air-calcined chromia-based catalysts and nitrogen-calcined chromia-based catalysts are prepared and used for a vapor-phase catalytic fluorination reaction in preparing difluoromethane. It has been found that the air-calcined catalysts show much higher catalytic activity than that of nitrogen-calcined catalysts in the above mentioned reaction, which is attributed to the formation of a Cr species with high oxidation state on the air-calcined catalyst. Moreover, when the catalyst precursor is treated with anhydrous hydrogen fluoride at low temperature, the crystallized catalyst is easily formed and the catalytic reaction activity is decreased.
Databáze: OpenAIRE