活性炭在过氧化氢氧化脱除二苯并噻吩中的催化作用

研究了几种活性炭在过氧化氢氧化二苯并噻吩(DBT)中的催化性能、氧化脱除机理以及碳表面化学对催化性能的影响。考察了活性炭的吸附性能与催化性能以及两者之间的关系、DBT在活性炭上的动态反应活性以及水相pH对其吸附性能和催化性能的影响;并将一种木质活性炭经过3种表面处理,研究了活性炭的表面化学对其催化性能的影响。结果表明:活性炭在过氧化氢氧化DBT中具有较高的催化活性,正辛烷中的DBT转化率可达到81%以上;木质粉末活性炭对DBT的吸附性能优于果壳炭和煤质颗粒活性炭;吸附容量大的活性炭,其催化性能也好;DBT在催化性能高的活性炭作用下的动态反应活性也高;水相pH在低于2的条件下有利于DBT在活性炭上的吸附和催化氧化。DBT的氧化脱除强烈依赖于表面羰基量,是由于表面羰基能加速过氧化氢产生自由基。

Catalysis of Activated Carbon in Oxidative Removal of Dibenzothiophene with Hydrogen Peroxide

Catalytic performance of several activated carbons,removal mechanism and effect of carbon surface chemistry on catalytic activities in oxidation of dibenzothiopene(DBT) with hydrogen peroxide catalyzed by the activated carbons were studied.Adsorptive and catalytic performances of the activated carbons and their correlation were investigated.Dynamic reactivity of DBT on the selected activated carbons was investigated.Moreover,the effects of the aqueous pH on DBT adsorption and the catalytic activities of the activated carbons were investigated.Finally,an activated carbon of wood origin was modified by three treatments.The effect of carbon surface chemistry on its catalytic properties was studied.Experimental results indicate that activated carbon has high catalytic activity,and conversion of DBT in n-octane solution can reach above 81%.Adsorption performance of powder wood carbons is higher than that of the fruit shell carbon and the coal-based carbons.The higher the adsorption capacity of the activated carbon is,the better its catalytic performance is.The better the catalytic performance of the activated carbon is,the higher dynamic reactivity of DBT on the activated carbon is.It is advantageous to the adsorption and oxidation of DBT when the aqueous pH is less than 2.The oxidative removal of DBT shows a strong dependence on the number of carbonyl group due to a factor: surface carbonyl groups can accelerate hydrogen peroxide to produce hydroxyl radicals.