GB1271710A - Treatment of exhaust gases from leaded motor fuels - Google Patents

Abstract

1,271,710. Alumina coated substrate. TEXACO DEVELOPMENT CORP. 10 Dec., 1969 [30 Dec., 1968], No. 60169/69. Heading B1E. [Also in Division F1] A catalytic alumina-coated structure comprises a substantially uniform film of alumina formed on a substrate by contacting the substrate with an aqueous solution of an alkali metal aluminate to form an adherent film of alumina trihydrate, separating the alumina coated structure from the solution and heating under calcining conditions for sufficient time to at least dehydrate the alumina trihydrate. After passing the gasses over the alumina coated structure of the invention they may be passed in contact with an oxidation catalyst e.g. Group VIII metals or Period 4 metals impregnated on the "bare" alumina structure. The substrate is preferably a metal, those specified being steel, stainless steel, alloy steel, iron, iron alloys, nickel, chrome-nickel alloys or titanium, but the substrate may be a refractory or ceramic, e.g. high melting glass, refractory metal oxides such as magnesia or silica, or refractory metal silicates or carbides. The configuration of the substrate may be balls, bars, chain, mesh, plates, saddles, sheet, tubes or wire, but it is preferred to use metal wool contained within a metal tubular casing. Sodium aluminate is the preferred reactant and it is preferred to calcine the alumina trihydrate to give gamma alumina.