Trifluoromethane (CHF3, HFC23, fluoroform) is one of most potent greenhouse gases and has a global warming potential which is 12,000 times that of CO2 and an atmospheric lifetime of 264 years.It is an unintended by-product of HCFC-22 (CHClF2) manufacture. Thus, it is of great practical significance to develop suitable technologies for the treatment of CHF3 in order to reduce emission of this compound and help mitigate global warming.

The decomposition of CHF3 was investigated over K2O/AC at temperatures 600-900oC and a space velocity of 4,300 h-1. The K2O/AC catalysts with a nominal 10 wt% K loading were prepared by impregnation with coconut originated activated carbon as support and KNO3 as precursor. It has been found that this catalyst shows a high and stable activity during the pyrolysis of CHF3 under the conditions studied. The gas phase decomposition of CHF3 commences at 700oC, but in the presence of catalyst, the reaction occurs at temperatures below 600oC and the conversion of CHF3 increases by 2-10 times between 600-850oC. More significantly, the catalytic decomposition gives rise to the formation of C2F4 and C3F6 as major products, which are highly valuable products and key monomers for the synthesis of Teflon and other fluoropolymers. As high as 40-60% of selectivity to C2F4 and 25-35% of selectivity to C3F6 were achieved. Other minor products include CF4, C2F6 and C3F8. The results of stability experiment showed that only a slight decrease of activity was observed after 12 h on stream.