B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
B—PERFORMING OPERATIONS; TRANSPORTING
B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
B01D—SEPARATION
B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
B01D53/34—Chemical or biological purification of waste gases
B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
B01D53/9459—Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts
B—PERFORMING OPERATIONS; TRANSPORTING
B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
B01J23/74—Iron group metals
B01J23/745—Iron
B—PERFORMING OPERATIONS; TRANSPORTING
B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper