吸附存储-间歇放电法氧化甲苯的反应过程研究

以SBA-15为催化剂,对比连续降解法和吸附存储-间歇放电法净化低浓度甲苯的活性,结果表明吸附存储-间歇放电法下甲苯去除率、碳平衡和CO2选择性更高.运用GC-MS分析了2种降解方式催化剂表面中间产物随时间的变化,苯甲醛进一步氧化分解进而打开苯环,是等离子体催化降解甲苯的控制步骤.对比SBA-15、Mn/SBA-15、Ag/SBA-15、AgMn/SBA-15 4种催化剂在吸附存储-间歇放电法下降解甲苯的活性.结果显示Ag和Mn的引入加速了对2-庚烯醇的氧化催化,AgMn/SBA-15表现出最好的碳平衡、CO2选择性.

Reaction process of toluene oxidation by adsorptive storage-intermittent discharge method

The effect of continuous discharge and adsorptive storage-intermittent discharge combined with SBA-15on toluene decomposition was investigated under ambient pressure and temperature. The results showed that adsorptive storage-intermittent discharge method exhibited higher toluene conversion, CO2 selectivity and better carbon balance compared to the former. The evolution of the intermediate products on the catalyst surfaces with time were also analysed by GC-MS in both methods. The results indicated that formaldehyde oxidation was the rate-determining step for toluene decomposition. Then, the activities of four different catalysts, SBA-15, Mn/SBA-15, Ag/SBA-15and AgMn/SBA-15were tested with dsorptive storage-intermittent discharge mode. AgMn/SBA-15catalyst exhibited the highest CO2 selectivity and the best carbon balance among the tested catalysts, which may be due to 2-heptene alcohol oxidation catalyzed by the addition of Ag and Mn.