NH_3低温选择性催化还原NO的研究

Selective Catalytic Reduction with NH_3 at Low Temperature

在固定床反应器中,利用瞬态响应技术和程序升温技术研究了低温时NH3选择性催化还原(SCR)NO的瞬态动力学及V2O5-WO3/TiO2催化剂活性的影响因素,试验结果表明:O2的体积分数增大,NO转化率增大;H2O的存在抑制了NO的转化率;SO2的存在提高了NO的转化率.低温时,SCR反应遵循Eley-Rideal机理,其反应速率依赖于催化剂表面的NH3覆盖度,但当NH3覆盖度大于NH3"临界"覆盖度时,则与NH3覆盖度无关.

The transient kinetics of the selective catalytic reduction（SCR）of NO with NH3 and the influence factors of V2O5-WO3/TiO2 catalyst activity at low temperature were studied in a fixed-bed reactor by temperature programmed technique and transient response technique.The experimental results showed that the promoting effect of oxygen on NO conversion was abtained,that SCR activity decreased when H2O was added,and that NO conversion was en-hanced with the presence of SO2.At low temperature,SCR reaction is in line with the Eley-Rideal pathway,and the rate of SCR reaction depended on catalyst surface NH3 coverage.While the reaction rate was independent of the NH3 coverage when it is above the NH3 critical coverage.