Catalysts for the redn of nitrogen oxides - comprising nickel and/or cobalt sulphide supported on nickel and/or cobalt

摘要

A catalyst for the redn. of N oxides in the exhaust gases from IC engines comprises Ni sulphide and/or Co sulphide supported on the same metal(s) as are contained in the sulphide(s). The catalyst is pref. produced by (a) treating an alloy of Al, Ni and/or Co with an alkali to dissolve 15-25% of the Al and passing H2S over the product, pref. at 200-300 degrees C and atmospheric pressure, until the sulphide layer is 10-100 mu thick; or (b) applying a layer of Ni/Co alloy (pref. by electrodeposition) onto a metal support (pref. an mild, stainless or heat-resisting steel or an Ni/Cr, Ni/Co/Fe alloy), and treating with H2S, pref. until the sulphide layer is 10-20 mu thick.