Supported catalyst and process for catalytic oxidation of volatile organic compounds

摘要

A catalyst for effective oxidation of volatile organic compounds (VOCs) includes 0.010-2 wt. % of a noble metal such as platinum in combination with 0.5-15 wt. % of a transition metal oxide such as chromium oxide (Cr. sub.2 O.sub.3), with at least the noble metal being deposited as a thin outer layer or shell not exceeding 0.10 mm thickness on a porous inert support such as alumina or silica having surface area of 10-400 m.sup.2 /g. The catalyst is made by adding the transition metal oxide such as chromium oxide (Cr.sub.2 O.sub.3) to the support material particles, and then subsequently mixing a solution of ammonium platinum nitrate with a suitable carrier liquid so as to form a "cluster" structure on the support material and which limits penetration of the active noble metal into the porous support, then drying, reducing, and calcining the metals- loaded support material. This catalyst composition and structure is highly effective for the oxidative destruction of VOCs in vapor form at concentrations of 1 ppm--5 vol. % and at reaction temperatures of 50. degree.-500° C., 0-600 psig pressure, and space velocity of 1000- 200,000 hr.sup.-1 to produce essentially only carbon dioxide and water products.