气相氧化处理对沥青基球状活性炭表面化学及吸附性能的影响  

The surface chemistry of pitch-based spherical activated carbon(PSAC)and the effect of gas-oxidation treatment on its adsorption performance

作　　者：刘朝军[1] 梁晓怿[1] 滕娜[1] 刘小军[1] 龙东辉[1] 詹亮[1] 张睿[1] 杨俊和[2] 凌立成[1] 

机构地区：[1]华东理工大学化学反应工程联合国家重点实验室,上海200237 [2]上海应用技术学院材料科学与工程学院,上海200235

出　　处：《新型炭材料》2010年第6期460-464,共5页New Carbon Materials

基　　金：国家自然科学基金(50672025);上海市科委支持项目~~

摘　　要：利用气相氧化处理对沥青基球状活性炭(PSAC)进行氧化改性,考察了氧化改性气氛中氧含量、氧化时间和氧化温度对PSAC表面化学性能的影响。用氮气吸附法表征了PSAC的孔结构,并研究了改性前后PSAC对苯酚吸附性能的变化规律。结果表明:改性前后PSAC的孔结构变化不明显;当氧化改性气氛中氧含量为20%,氧化时间为5h以及氧化温度分别为400℃和450℃时,沥青基球状活性炭的表面酸性官能团由0.11m eq/g分别增加到1.22m eq/g、1.60m eq/g,碱性官能团由0.52m eq/g分别减少到0.03m eq/g、0.02m eq/g;随着表面酸性官能团数量的逐渐增加,PSAC亲水性能逐渐增强,使得溶剂水对吸附位产生强烈的竞争吸附,最终导致PSAC对苯酚的吸附等温线由L型向S型转变。Pitch-based spherical activated carbon（PSAC） was modified by gas mixtures of nitrogen and oxygen.Nitrogen adsorption was used to obtain the pore structure of the PSAC.The phenol adsorption performance of the PSAC before and after modification was investigated.Results showed that there is no obvious texture change of PSAC after air oxidation.When the PSAC was modified with a gas mixture having an oxygen content of 20% for 5h at 400℃ and 450℃,the surface acidic groups increased from 0.11 to 1.22,1.60meq/g,while basic groups decreased from 0.52 to 0.03,0.02meq/g,respectively.The adsorption capacity of phenol on the PSAC decreased as the surface acidic groups increased because its wettability was improved.Water molecules were more competitive for the adsorption sites than the adsorbate in such a situation.The adsorption isotherms of phenol on PSAC changed from type L to type S with an increase of surface acidic groups.

关 键 词：沥青基球状活性炭(PSAC) 空气氧化 孔结构 吸附性能 

分 类 号：TQ424.1[化学工程]