WO3/ZrO2 Strong Acid as a Catalyst for the Decomposition of Chlorofluorocarbon (CFC-12)

Introduction Chlorofluorocarbons (CFCs) diffusing to the stratosphere is a major reason for ozone depletion1]. Also CFCs has been claimed to be notorious for its greenhouse effect2]. So, recently it has become very important to eliminate CFCs as far as protecting the ozone layer surrounding the earth is concerned. Among various kinds of approaches to do destruction to CFCs, the catalytic decomposition seems to be the most practical and energetically favorable one, especially for treating small amounts of CFCs3,4]. Recently, Fu et al.3] reported that TiO2 modified with H2SO4 was much more active than TiO2 for the decomposition of CFC-12 in the presence of water vapor, and they attributed this tremendous enhancement in activity to the superacidic property of the sulfated catalyst. Their research results substantially stimulate us to investigate the catalytic decomposition of CFC-12 in the presence of water vapor over WO3/ZrO2 strong acid, which is more thermally stable than the sulfated oxides superacids5].