预氧化处理椰壳制备微孔活性炭及性能研究

Preparation of microporous activated carbon from pre-oxidized coconut shell and properties study

以印尼椰壳为原料,通过预氧化、碳化、活化成功制备了比表面积和微孔含量高的椰壳活性炭,预氧化有利于椰壳活性炭比表面积尤其是微孔比表面积的提高。重点考察了预氧化温度对所制备椰壳活性炭收率、密度、表面官能团、孔结构参数的影响。结果表明,预氧化过程中,由于发生了脱水、羟基氧化、脱羧等反应,O/C、羰基、羧基、酯基等含氧官能团的强度均随温度升高而先增强后减弱,在预氧化温度为280℃时达到最大。所制备椰壳活性炭比表面积、孔容、微孔率等随温度升高先升高后下降,在330℃制备的椰壳活性炭各项孔结构参数最优。

Using coconut shell from Indonesia as raw material,the activated carbon with a high specific surface area and large micropore content is successfully prepared through pre-oxidation,carbonization and activation.It is proved that pre-oxidation is beneficial to increasing specific surface area of coconut shell activated carbon,especially that of the micropore.The influences of pre-oxidation temperature on the yield,density,surface functional groups and pore structure of the prepared coconut shell activated carbon are investigated.It is shown by results that the strengths of O/C,carbonyl,carboxyl,ester and other oxygen-containing functional groups increase firstly and decrease then with the increasing temperature because dehydration,hydroxyl oxidation and decarboxylation happen during the pre-oxidation process,those reach the maximum at 280℃.The specific surface area,pore volume and microporosity of the prepared coconut shell activated carbon firstly increase and then decrease with the increasing temperature.Its pore structure parameters reach the optimal at 330℃.