MnCeOx/沸石催化剂对工业典型VOCs的催化性能

以沸石为载体制备了锰铈复合氧化物催化剂(记为:MnCeO_x/沸石催化剂),探究了催化剂对工业典型VOCs的二元催化性能,并对催化剂进行BET、XRD及SEM表征。结果表明:Ce的加入,促进了Mn的分散,提高了MnCeO_x/沸石催化剂的活性;当n(Mn)∶n(Ce)为1∶1,负载率为20%,焙烧温度为500℃时,催化剂的活性最高,其对甲苯的起燃温度(T50)和完全燃烧温度(T₉₀)分别为155,255℃;单组分实验中,催化剂对3种有机物均表现出较高活性,转化率达到90%时的反应温度均在275℃以下,其活性顺序为乙酸乙酯>甲苯>丙酮,主要受反应活化能大小及分子极性的影响;二元催化实验中,由于竞争吸附的影响,3种物质的T50和T90较单组分均分别提高了8～13,14～38℃。

CATALYTIC PERFORMANCE OF TYPICAL VOCs OVER MnCeOx/ZEOLITE CATALYST

Manganese-cerium composite oxides catalyst was prepared with zeolite as the carrier. The binary catalytic performance of the catalyst for industrial typical VOCs was investigated, and the catalyst was characterized by BET, XRD and SEM. Results showed that the addition of the cerium promoted the dispersion of the manganese and improved the activity of the composite oxide catalyst.The catalytic performance of MnCeO_x/zeolite was the best with n(Mn)∶n(Ce) of 1∶1, loading ratio of 20% and calcination temperature of 500 ℃, with initial and complete combustion temperatures of toluene at 155 ℃ and 255 ℃, respectively. In the single component experiment, the catalysts for three organics all showed higher activity, and the temperature of conversion of 90% was below 275 ℃; the catalytic performance decreased in the order of ethyl acetate, toluene and acetone, which was mainly affected by the level of the activation energy as well as their polarity of molecule. In the binary catalytic experiment, T₅₀ and T₉₀ of three organics increased respectively by 8~13 ℃ and 14~38 ℃ than that in the single component experiment, due to the competitive adsorption.