Vehicle exhaust gas systems
AssigneeArvin UK Limited
InventorsPhilip G. Harrison, Peter J. F. Harris
Life of this patent
Estimating the term…
Abstract
2-way and 3-way catalyst compositions comprising tin(IV) oxide (SnO.sub.2) and chromium(VI) oxide (CrO.sub.3) are disclosed for use in catalytic converters for vehicle exhaust gas systems, such catalyst compositions being effective in the catalytic oxidation of carbon monoxide and unburnt hydrocarbons, and in the catalytic reduction of nitrogen oxides contained in the vehicle exhaust.
Claims8
A method for the catalytic oxidation of carbon monoxide and unburnt hydrocarbon components of vehicle exhaust gas streams, which comprises using as the catalyst a mixed oxide catalyst composition consisting essentially of a calcined mixture of tin (IV) oxide (SnO.sub.2) and chromium (VI) oxide (CrO.sub.3) free from platinum and other noble metals or noble metal oxides, and containing a Sn:Cr weight ratio (calculated as SnO.sub.2 :CrO.sub.3) in the range of 1:99 to 99:1, said catalyst composition having been obtained by impregnating tin (IV) oxide (SnO.sub.2) with chromium (VI) oxide (CrO.sub.3) to form an impregnated product consisting of tin (IV) oxide (SnO.sub.2) and chromium (VI) oxide (CrO.sub.2) and calcining the resulting impregnated product.
Dependencies are inferred from the claim text.