PROCESSING METHODS AND FORMULATIONS TO ENHANCE STABILITY OF LEAN-NOx-TRAP CATALYSTS BASED ON ALKALI- AND ALKALINE-EARTH-METAL COMPOUNDS

• Main Authors: MCCABE ROBERT, JEN HUNGWEN, GRAHAM GEORGE
• Format: Patent
• Language: English
• Published: 16.02.2006
• Subjects: 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

The present invention provides a coarsening resistant automotive exhaust catalyst composition. The composition of the invention comprises a metal or metal-containing compound and a component having alkali metal or an alkaline-earth metal ions bonded to a conjugate base oxide of an inorganic acid. The inorganic acid for which the base oxide is conjugate has a Ka such that the automotive exhaust catalyst composition resists phase transitions that reduce surface area. The present invention also provides a NOx trap which incorporates the exhaust catalyst composition of the invention. Finally, a method of inhibiting coarsening in automotive exhaust catalyst is also provided.