捕获法测定介质阻挡放电降解甲苯中产生的羟基自由基

Detection of hydroxyl radical produced in DBD system during toluene decomposition with capture method

用水杨酸浸渍膜捕集-高效液相色谱(HPLC)法测定介质阻挡放电降解甲苯中羟基自由基(.OH)的生成量.考察了能量密度(SIE)、相对湿度(RH)、背景气氛、催化剂对.OH产生量的影响.实验表明,.OH量随能量密度的增大而增加,能量密度从140 J.L-1增至320 J.L-1时,.OH量从5.9×1013个.cm-3增加到4.36×1014个.cm-3;反应中存在一个最佳RH值20%;通过改变背景气氛确认了背景气体中的水汽为.OH的主要来源,适量的O2存在可增强自由基的产率,但其作用远小于水汽,惰性气体氩气的加入可以大大提高.OH产率;催化剂的加入使得气流中的.OH量大大减少.

A film impregnated with salicylic acid coupled with high performance liquid chromatography（HPLC） was developed to determine hydroxyl radicals formed in DBD reactor.Effect of trapping time,specific input energy（SIE）,relative humidity（RH）,various background gases as well as catalyst on the quantities of OH were investigated.It was found that the quantities of OH increased with the increase of SIE.When SIE increased from 140 J·L-1 to 320 J·L-1,the amount of OH increased from 5.9×1013 radicals·cm-3 to 4.36×1014 radicals·cm-3.In the reaction RH of 20% was optimal.By changing the background gases,water vapor was identified to be the main source of OH.Moderate amount of O2 was favorable to the generation of OH,but the role of it was less important than water.Argon could enhance the formation of OH.The addition of catalyst greatly reduced the generation of OH in the gas stream.