This invention relates to a catalytic composite and a process for reducing the ignition temperature of diesel soot. The process comprises contacting an exhaust gas from a diesel engine, which exhaust contains diesel soot, with a catalytic composite. The composite comprises a sulfur resistant refractory inorganic oxide selected from the group consisting of titania, zirconia, silica, silica-alumina and alumina which has been treated to be sulfur resistant, i.e. alumina treated with titania, zirconia, etc. which has deposited thereon at least one catalytic element selected from the group consisting of Pt, Pd and Rh. The inorganic oxide may be deposited on ceramic or metallic traps.