Catalytic removal of perchloroethylene (PCE) over supported chromium oxidecatalysts

The oxidation of perchloroethylene (PCE) was investigated over chromium oxi de catalysts supported on SiO2 SiO2-Al2O3, activated carbon, mordenite type zeolites, MgO, TiO2 and Al2O3. Supported chromium oxide catalysts were mor e active than any other metal oxide catalysts including noble metal examine d in the present study. PCE removal activity of chromium oxide catalysts ma inly depended on the type of supports and the content of metal loaded on th e catalyst surface. TiO2 and Al2O3 containing high surface areas were effec tive for the high performance of PCE removal, since the formation of well d ispersed Cr(VI) active reaction sites for the present reaction system, was enhanced even for the high Cr loading on the catalyst surface. CrOx catalys ts supported on TiO2 and Al2O3 also exhibited stable PCE removal activity a t a low feed concentration of PCE of 30 ppm up to 100 h at 350 degreesC. Ho wever, significant catalyst deactivation was observed at high PCE concentra tion 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.