Application of Spinel-Type Cobalt Chromite as a Novel Catalyst for Combustion of Chlorinated Organic Pollutants

Abstract

Various chromium-containing; catalysts were tested fdr the total oxidation of trichloroethylene (TCE) as a model reaction for the catalytic combustion of chlorinated organic pollutants. A spinel-type cobalt chromite (CoCr(2)O(4)) among others was proven to be a very promising catalyst showing higher activity and higher CO(2) selectivity than traditional alumina supported chromia. Even if both Cr(3+) and Cr(6+) species were observed on the surface of CoCr(2)O(4), the Cr(6+) species was stable under reducing environment. The presence of Cr(3+)-Cr(6+) pair sites and the effect of red ox treatments on the activity were investigated to explain the nature of possible active sites for TCE decomposition. Higher selectivity to CO(2) of CoCr(2)O(4) was ascribed to the abundance of its Cr(3+) species, together with its activity for water gas shift reaction.