Low-Temperature Thermal and Photoactivation of TiO2-Supported Ru, Rh, and Cu Catalysts for CO-NO Reaction

Abstract TiO 2 (P25)-supported Ru catalysts are active for NOCO reaction at temperatures as low as ambient in a batch reactor. Reaction products are CO 2 , N 2 O, and N2. In a fixed-bed reactor, this reaction was monitored from 90 to 235°C. The activity increased exponentially above 150°C. On illumination with light energy (λ ≤ 390 nm), the rate of decomposition of N 2 O, a product formed during the reaction, is enhanced significantly. N 2 O has been shown to react with CO as well. All photoactivation experiments have been performed in batch reactors. Photoprocesses are support related and a reaction mechanism has been put forth to explain the observed phenomena. The catalyst prepared by the deposition-precipitation technique shows selective dispersion of Ru particles over the rutile phase of TiO 2 from a mixture of 80% anatase and 20% rutile (composition of P25). Addition of Rh and Cu increases the N 2 O decomposition property of the catalyst.