Catalysis Today, Vol.191, No.1, 154-158, 2012
Preparation and characterization of TiO2-based plasma-sprayed coatings for NOx abatement
To minimize the formation of environmentally hazardous emissions, the catalytic reduction of NO by CO at metal oxide surfaces deposited by plasma spray technology on a Fe-Cr alloy support was studied. The paper outlines an experiment performed on a bench-scale reactor, describes the preparation of a catalytic monolithic reactor, the operating conditions as well as the properties of new-type catalytic coatings. As noted earlier in [1], the catalytic coatings containing an active component CuO effectively reduce the content of CO in the exhaust gas by over 90%. To enhance the NOx reduction by CO on the catalyst, TiO2 as a promoter and Ni powder as a catalyst were additionally incorporated in the initial mixture for catalytic coating formation. The structural and functional properties of the active layer substrate system were analysed by methods of scanning electron microscopy (SEM), BET surface area, thermal analysis (DSC-TG), X-ray diffraction (XRD) and determination of roughness parameters. All the obtained coatings showed a good density, thermal stability and physical strength. However, irregularly agglomerated metal oxide layers had been formed in some places. The most active catalytic coating of Ni-Cu/TiO2-Al2O3 type showed an 80-90% removal for both NO and CO (CO/NO = 3) in the oxidizing gas mixture. (c) 2012 Elsevier B.V. All rights reserved.