Catalysts for reducing nitrogen oxides to molecular nitrogen in a superstoichiometric medium of oxidizing compounds, process for preparation, and uses

• Main Authors: MOUCHOT; PAUL, DURAND; DANIEL, MABILON; GIL
• Format: Patent
• Language: English
• Published: 07.04.1998
• Edition: 6
• Subjects: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSEGASES [GHG]; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; THEIR RELEVANT APPARATUS; TRANSPORTING

Described is catalyst that is active and selective for reducing to molecular nitrous oxides contained in a superstoichiometric medium of oxidizing agents, said reduction being conducted with agents such as carbon monoxide, hydrogen, hydrocarbons, alcohols, ethers, and other oxidized organic compounds and also with ordinary fuels such as gasolines, gas oils, liquefied gases, and compressed natural gases, whereby said catalyst comprises: at least one refractory inorganic oxide, including alumina; at least one element (A) that belongs to the group of rare earths; at least one element (B) that belongs to groups VIB, VIIB, VIII and IB of transition metals; at least one metal (C) that belongs to the group of precious metals of the platinum family, and optionally at least one element (D) that belongs to group IIA of alkaline-earths; at least a portion of elements (A) is combined with alumina to form at the surface of the latter a microlayer of rare-earth aluminate.