INFRARED STUDY OF THE OXIDATION OF HEXAFLUOROPROPENE ON TIO2

Transmission infrared spectroscopy is employed to study the oxidation of C3F6 on TiO2 particles. TiO2, alone, without dispersion of any tran sition metals, is capable of oxidizing C3F6 to completion in O-2(g) at similar to 600 K. CO2 and CO were found to be the two major products. The initial stage of the C3F6 oxidation on TiO2 follows the conventio nal redox mechanism: the Mars-van Krevelen cycle which involves both l attice and gaseous oxygen. CF3COO(a) was found to be a reaction interm ediate on the TiO2 surface. Water was observed to reduce the oxidation rate of C3F6. A mechanism involving surface CF3COO(a) and FCOO(a) is proposed. Consumption of Ti occurs, producing TiF4(g) during the oxida tion reaction.