A comparative study of metal oxide and sulfate catalysts for selective catalytic reduction of NO with NH3.
The properties and characteristics of metal oxide and sulfate catalysts with different active elements for selective catalytic reduction of NO with NH3were investigated. Cerium-based oxide catalyst showed the widest temperature window for NOxremoval and manganese-based oxide catalyst exhibited the best catalytic performance at low temperature. For all the catalysts, the SCR activities at low temperature were directly related with the redox abilities of catalysts. The existence of sulfate groups inhibited the redox abilities of active species for sulfate catalysts compared with the metal oxide catalysts. The catalytic activities of CeWTi-S and MnWTi-S were seriously decreased in contrast to CeWTi-N and MnWTi-N. The temperature window of CuWTi-S was shifted toward higher temperature comparing with CuWTi-N. The FeWTi-N and FeWTi-S catalysts both showed high NOxconversion in the temperature range between 300°C and 400°C and N2O concentrations for iron-based samples were least among the same kind of catalysts. The abundance of acid sites and weak stability of surface sulfate groups for iron- and copper-based sulfate catalysts might be the main reasons accounting for the better NOxconversion in the medium-temperature range.
a Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment , Southeast University , Nanjing , People's Republic of China.
Lin
L
Zhu
a Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment , Southeast University , Nanjing , People's Republic of China.
Zhaoping
Z
Zhong
a Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment , Southeast University , Nanjing , People's Republic of China.
Han
H
Yang
b College of Energy and Power Engineering , Nanjing University of Aeronautics and Astronautics , Nanjing , People's Republic of China.
Chunhua
C
Wang
D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control; D000641:Ammonia / Q000737:chemistry*; D002384:Catalysis; D019216:Metals, Heavy / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*; D013696:Temperature
D000393:Air Pollutants; D019216:Metals, Heavy; D010087:Oxides; D013431:Sulfates; D009569:Nitric Oxide; D000641:Ammonia
SCR; catalyst acidity; metal oxides; redox ability; sulfates