富氧条件下乙炔选择催化还原NOx

Acetylene as a reducing agent of metal exchanged HY catalysts, for selective catalytic reduction of NO in the reaction system of 0.16% NO, 0 （C2H2-SCR） was investigated over a series 08% C2H2, and 9.95% O2 （volume percent） in He. 75% of NO conversion to N2 with hydrocarbon efficiency about 1.5 was achieved over a Ce-HY catalyst around 300 ℃. The NO removal level was comparable with that of selective catalytic reduction of NOx by C3H6 reported in literatures, although only one third of the reducing agent in carbon moles was used in the C2H2-SCR of NO. The protons in zeolite were crucial to the C2H2-SCR of NO, and the performance of HY in the reaction was significantly promoted by cerium incorporation into the zeolite. NO2 was proposed to be the intermediate of NO reduction to N2, and the oxidation of NO to NO2 was rate-determining step of the C2H2-SCR of NO over Ce-HY. The suggestion was well supported by the results of the NO oxidation with O2, and the C2H2 consumption under the conditions in the presence or absence of NO.

Using Acetylene for Selective Catalytic Reduction of NO in Excess Oxygen

Acetylene as a reducing agent for selective catalytic reduction of NO (C₂H₂‐SCR) was investigated over a series of metal exchanged HY catalysts, in the reaction system of 0.16% NO, 0.08% C₂H₂, and 9.95% O₂ (volume percent) in He. 75% of NO conversion to N₂ with hydrocarbon efficiency about 1.5 was achieved over a Ce‐HY catalyst around 300 °C. The NO removal level was comparable with that of selective catalytic reduction of NO_x by C₃H₆ reported in literatures, although only one third of the reducing agent in carbon moles was used in the C₂H₂‐SCR of NO. The protons in zeolite were crucial to the C₂H₂‐SCR of NO, and the performance of HY in the reaction was significantly promoted by cerium incorporation into the zeolite. NO₂ was proposed to be the intermediate of NO reduction to N₂, and the oxidation of NO to NO₂ was rate‐determining step of the C₂H₂‐SCR of NO over Ce‐HY. The suggestion was well supported by the results of the NO oxidation with O₂, and the C₂H₂ consumption under the conditions in the presence or absence of NO.