摘要:
A process for preparing an oxidation/reduction catalyst system includes providing a sol-gel precursor; providing a metal oxide wash coat mixture; and dispersing the sol-gel precursor in the metal oxide wash coat mixture to provide a dispersion of sol-gel precursor in metal oxide wash coat mixture. This dispersion of sol-gel precursor in metal oxide wash coat mixture is then deposited on a support, which is subsequently thermally-treated in an oxygen-containing environment to drive off volatiles and oxidize metallic components, thereby producing a thermally-treated support. Finally, a noble metal coating is applied to the thermally-treated support.
摘要:
An exhaust gas treatment system having an exhaust gas inlet section, an oxygen enrichment system, catalyst holding arms, and an exhaust gas outlet section is disclosed. The exhaust gas inlet and outlet sections can be designed to mate to existing exhaust gas plumbing systems for industrial facilities. The optional oxygen enrichment system helps optimize catalytic performance by maintaining excess oxygen in the exhaust gas stream and by imparting greater turbulence to the exhaust gas stream. Disposed within each catalyst holding arm is at least one catalyst coated substrate where the catalytic oxidation of formaldehyde and other volatile organic compounds occurs. The catalytic substrate can be catalyst coated bricks, particles, beads, fabrics, or filter materials. Each catalyst holding arm can be selectively closed off using upstream and downstream isolation valves. Catalyst coated substrate longevity can be increased by the inclusion of an optional filter upstream of the catalyst coated substrates.
摘要:
The invention described herein involves a novel approach to the production of oxidation/reduction catalytic systems. The present invention serves to stabilize the tin oxide reducible metal-.oxide coating by co-incorporating at least another metal-oxide species, such as zirconium. In one embodiment, a third metal-oxide species is incorporated, selected from the group consisting of cerium, lanthanum, hafnium, and ruthenium. The incorporation of the additional metal oxide components serves to stabilize the active tin-oxide layer in the catalytic process during high-temperature operation in a reducing environment (e.g., automobile exhaust). Moreover, the additional metal oxides are active components due to their oxygen-retention capabilities. Together, these features provide a mechanism to extend the range of operation of the tin-oxide-based catalyst system for automotive applications, while maintaining the existing advantages.