procedure for the regeneration of lead contaminated catalysts for the purification of exhaust gases from brennkraftmaschinen

摘要

A process for treating a solid oxidation catalyst which during prior use has become contaminated with from 5-30% by weight of lead and has during such prior use been contacted by an oxidizing p gas, is characterized in that the activity of the catalyst is increased by contacting the catalyst with a reducing gas between 93 and 1093 DEG C. Specified catalyst constituents are V, Cr, Mo, W, Cu, Ag, Au, Pt, Pd, Ir, Rh, Co, Ni, Fe. Specified combinations are Co-Cu, Cu-Fe, Cu-Cr, Cr-Ni, Co-Cr, Mn-Cr, Mn-Fe, Pt-Fe, Pt-Co, Pt-Ni, Pd-Fe, Pd-Co, Pd-Ni, Pd-Cu, Pd-Pt, Pd-Cu-Co, Pt-Cu-Co, Co-Cu-Pd-Ni, and Pt-Co-Pd. Specified supports are Al2O3, TiO2, SiO2, B2O3, Al2O3-SiO2, Al2O3-ZrO2 and Al2O3-SiO2-ZrO2. Examples are given. Specification 690,825 is referred to.