Removal of NOx with cobalt phthalocyanine supported on Y-type faujasite and alumina

The oxidative removal of NO with oxygen over a catalyst consisting of P-form cobalt phthalocyanine supported on SiO2, TiO2, Y-type faujasite, and alumina was studied at 30degreesC. The order of NOx adsorption capacity is as follows: Co-Phc/Al2O3 > Co-Phc/YZ much greater than YZ > Al2O3 > Co-Phc/SiO2, Co-Phc/TiO2, SiO2, TiO2 = 0 > Co-Phc(beta) = 0. The catalysts, Co-Phc/YZ and Co-Phc/Al2O3, were regenerated by water washing and could be used again. Infrared spectra for Co-Phc/YZ and Co-Phc/Al2O3 indicate that the removed NOx exists in the catalyst surface as adsorption species of NO, NO2 and NO3-. The superhyperfine structures of ESR spectra for Co-Phc/YZ and Co-Phc/Al2O3 support that the Co-N bonding occurs on admitting a mixture gas of oxygen (10 Pa) and NO (0.2 Pa). Therefore, it is concluded that the beta-form cobalt phthalocyanine supported on alumina and Y-type faujasite is effective for the oxidative removal of NO at 30 degreesC. (C) 2002 Elsevier Science B.V. All rights reserved.