Catalytic removal of perchloroethylene (PCE) over supported chromium oxide catalysts

The oxidation of perchloroethylene (PCE) was investigated over chromium oxide catalysts supported on SiO2 SiO2-Al2O3, activated carbon, mordenite type zeolites, MgO, TiO2 and Al2O3. Supported chromium oxide catalysts were more active than any other metal oxide catalysts including noble metal examined in the present study. PCE removal activity of chromium oxide catalysts mainly depended on the type of supports and the content of metal loaded on the catalyst surface. TiO2 and Al2O3 containing high surface areas were effective for the high performance of PCE removal, since the formation of well dispersed Cr(VI) active reaction sites for the present reaction system, was enhanced even for the high Cr loading on the catalyst surface. CrOx catalysts supported on TiO2 and Al2O3 also exhibited stable PCE removal activity at a low feed concentration of PCE of 30 ppm up to 100 h at 350 degreesC. However, significant catalyst deactivation was observed at high PCE concentration of 10 000 ppm. CrOx /TiO2 revealed stronger water tolerance than CrOx/Al2O3 due to the surface hydrophobicity. (C) 2000 Elsevier Science B.V. All rights reserved.