Carbon monoxide fluorination using alumina-supported cobalt trifluoride: a proof of concept

Abstract

Carbonyl fluoride is a versatile compound commonly used in fluorine chemistry. Its conventional synthesis route is the fluorination of carbon monoxide with elemental fluorine. The formation of carbon tetrafluoride as a byproduct, reducing product purity, makes this route problematic. An alternative approach is presented here: the use of alumina-supported cobalt trifluoride in a packed-bed reactor. The cobalt trifluoride was prepared by wet impregnation of the alumina with cobalt nitrate, calcination to form the cobalt mixed oxide, and fluorination of the oxide with fluorine gas to form the cobalt trifluoride. The prepared cobalt trifluoride was then used to fluorinate carbon monoxide in a heated packed bed reactor. Inline FTIR analysis confirmed the formation of carbonyl fluoride with characteristic bands at 976, 1253, and 1928 cm−1 clearly visible. There was no band indicative of the presence of carbon tetrafluoride detectable at 1278 cm−1. It can, therefore, be concluded that relatively pure carbonyl fluoride can be produced using cobalt trifluoride as fluorinating agent.