Contaminated gas, waste gas and vapour purificn. - by photocatalysis on semiconductor oxide, esp. titanium di:oxide treated with electrolyte increasing capillary condensation and doped with inorganic halogen cpd.

摘要

Purificn. of (waste) gases and vapours, which may contain aerosols and are contaminated or mixed with undesirable chemical substances, involves a photocatalysis reaction on the surface of semiconductor oxide catalysts (I), esp. TiO2, in a closed or open system, using a fluidised or fixed bed catalyst; and opt. washing out the mineralisation prods. formed by photocatalysis. The novel features are that (a) (I) is treated with liquid or solid agent (II), which acts as electrolyte and improves capillary condensation, i.e. mineral acid, alkali, salt or hydrolysis prods. (IIA) or mixts. or these; and/or (b) doped with inorg. halogen cpd(s). (III), excluding pure F cpds., as halogen radical source; or (c) doped with agent(s) (IV) combining the properties and functions of (a) and (b). -