反应条件对等离子体脱除吸附于Cu-Ce/AC表面NOx的影响

以放电等离子体协同催化法对吸附在Cu-Ce/AC上的NOx进行脱除，研究了不同的放电条件和添加水蒸气对脱除NOx的影响。结果表明，对于同轴圆筒形反应器，催化剂量一定时，放电长度增加，吸附态NOx去除率先升高后下降；放电电压增大，吸附态NOx去除率升高，原因在于放电反应区内能量密度和活性粒子分布状态改变。根据NOx程序升温脱附（TPD），TPD低温位（x更容易被放电等离子体脱除，放电长度和放电电压能够影响不同吸附位上NOx的去除效率。适宜条件下，吸附态NOx去除率最高达到93.3%。循环吸附-等离子体脱除NOx进行10次后，NOx脱除率在92%以上。在混合气中添加5%水蒸气提高了等离子体对吸附态NOx的去除率，但导致循环吸附-等离子体脱除NOx效率下降。原因是H2O与NOx竞争吸附带来的负面效应大于等离子体中H2O提供自由基与吸附态NOx反应所带来的正面效应。

Effect of reaction conditions on removal of adsorbed NOx over Cu-Ce/AC by plasma

Research was conducted on plasma-discharge-assisted catalytic conversion of adsorbed NOx over Cu-Ce/AC. The effects of different discharge conditions and water vapor on NOx removal were investigated. Results showed that for the coaxial cylindrical reactor with a fixed catalyst, adsorbed NOx removal increased and then decreased as discharge length increased. When discharge voltage increased, adsorbed NOx removal increased. This was related to the energy density and active species dispersion in the discharge reaction. According to NOx temperature-programmed desorption (TPD), the adsorbed NOx over low-TPD (x over different adsorptive sites. The removal of adsorbed NOx reached 93.3% under proper conditions. In ten adsorption and plasma cycles, NOx removal was higher than 92% each time. Five percent water vapor improved adsorbed NOx removal in plasma, but led to a decrease in de-NOx efficiency in adsorption-plasma cycles owing to competitive adsorption between H2O and NOx. The negative effect caused by competitive adsorption was more significant than the positive effect caused by the discharge reaction of adsorbed NOx and radicals produced from H2O.