Use of Strontium-Lanthanum Cobaltate as a High Temperature Catalyst for NOx Reduction

摘要

The primary objective of this work was to assess whether Strontium- Lanthanum Cobaltate shows promise as a high temperature catalyst for NO(x) reduction as an initial step in a program to develop useful NO(x) catalysts. The determination of the thermodynamic and kinetic stability of the active oxygen deficient phases in NO(x) atmospheres and the initial evaluation of the effectiveness of the catalyst for NO(x) reduction were secondary objectives to be included in this assessment. From XRD, DTA and simultaneous TGA/DSC measurements the A-site deficient composition was found to be chemically and structurally stable over a wide range of temperatures in air and simulated exhausts. This material will catalyze the reduction of NO to N2 in the presence of CO under fuel-lean, stoichiometric and fuel rich conditions, and is particularly effective at low temperature. Combining substrate materials which seem to erhance NO reduction at high temperatures with the perovskite catalyst, which works best at lower temperatures, holds promise as a synergistic emission control system.