DECOMPOSITION OF P-CHLOROPHENOL BY WET OX IDATION IN THE PRESENCE OF SUPPORTED NOBLE-METALS CATALYSTS

OKITSU K HIGASHI K NAGATA Y DOHMARU T TAKENAKA N BANDOW H MAEDA Y

K. Okitsu et al., DECOMPOSITION OF P-CHLOROPHENOL BY WET OX IDATION IN THE PRESENCE OF SUPPORTED NOBLE-METALS CATALYSTS, Nippon kagaku kaishi, (3), 1995, pp. 208-214

12

GIAPPONESE

Article

Chemistry

Nippon kagaku kaishi → ACNP

0369-4577

3

1995

208 - 214

ISI

0369-4577(1995):3<208:DOPBWO>2.0.ZU;2-#

Decomposition of p-chlorophenol (P-CP) was carried out at 150 degrees C under an oxygen pressure of 0.3 MPa in aqueous solutions, and the ef fect of noble metals supported on alumina or titania was studied. The decomposition of P-CP was accelerated by the addition of all the catal ysts except silver. The activites of the catalysts were in the order o f Pt much greater than Pd>Ru>Rh>Ag. In the case of 5% platinum support ed on alumina, the conversion of p-CP and reduction in TOC after 30 mi n were 90% and 89%, respectively, indicating that p-CP was mainly deco mposed to give carbon dioxide and water. The effects of the platinum s upported on various titania on the decomposition of p-CP and on the re duction in TOC were studied. The rate of the reduction was found to be higher on the catalyst with anatase-type titania than that with rutil e-type one. We also found that the catalytic activity was increased wi th decreasing sizes of titania. By-products formed during oxidation of p-CP were mainly organic acids, such as maleic acid, malonic acid, ac etic acid, and chloroacetic acid. Most of these intermediate products were further decomposed ata-considerably high rate. The decomposition of P-CP was supposed to proceed via free radical reaction, as well as hydrolysis and decarboxylation.