低温等离子体协同锰基催化剂降解甲苯、邻二甲苯的实验研究

Experimental Study on Degradation of Toluene and O-xylene by Non-thermal Plasma with Manganese Catalyst

VOCs的化学成分复杂,对于人体健康和生态环境产生潜在威胁。文章选取了甲苯和邻二甲苯两种典型的苯系物VOCs,制备5种Cu-Mn/γ-Al_(2)O_(3)系列催化剂并进行XRD、BET和XPS表征。将催化剂置于DBD反应器的放电区域来降解苯系物,探寻其降解效果和副产物生成情况。实验结果表明,Cu掺杂的MnO_(2)催化剂的引入显著提高了VOCs去除率和CO_(2)选择性。其中,等离子体催化系统中催化剂Cu_(0.15) Mn的性能最佳,甲苯和邻二甲苯的去除率可达100%,CO_(2)的选择性为92.73%,同时能抑制副产物O_(3)和NO_(2)的产生。催化剂的表征结果表明,Cu-Mn固溶体中Cu和Mn的协同作用可以提高表面活性氧的量和还原性,从而提高催化性能。

The chemical composition of volatile organic compounds(VOCs)is complex,and the potential threaten of VOCs to human health and ecological environment were widely proven.Two typical benzene VOCs,toluene and o-xylene,were selected to prepare five Cu-Mn/γ-Al_(2)O_(3) series catalysts and characterized by x-rays diffraction(XRD),Brunauer,Emmett,Teller’s test(BET)and x-ray photoelectron spectroscopy(XPS).The catalyst was filled into the discharge area of dielectric barrier discharge reactor to form a plasma catalytic system for the degradation of benzene series,and the degradation effect and by-product formation were investigated.The experimental results shown that the introduction of Cu-doped MnO_(2) catalyst significantly improved VOCs removal efficiency and CO_(2) selectivity.Among them,the catalyst Cu_(0.15) Mn in the plasma catalytic system shown the best performance,the removal rate of toluene and o-xylene can reach 100%,the selectivity of CO_(2) reached 92.73%,and the production of by-products O_(3) and NO_(2) can be inhibited.The results shown that the synergistic effect of Cu and Mn in Cu-Mn solid solution can increase the amount and reduction of reactive oxygen species on the surface,so as to improve the catalytic performance.