摘要
选择四种不同配位基团的双齿配位分子乙二胺(EN)、乙醇胺(EA)、乙二醇(EG)和丙二酸(MA)对CoMo/γ-Al_2O_3催化剂改性,比较了它们对二苯并噻吩HDS性能的影响。结果表明,其活性顺序为CoMo(EN)>CoMo(EA)>CoMo(EG)≈CoMo(MA)>CoMo,反应以直接脱硫路径为主,随反应温度升高,加氢路径的占比增加,加入配合物后可以促进加氢路径脱硫,CoMo(EN)催化剂具有最高的加氢活性。采用UV-vis、EA、XPS和HRTEM等手段对催化剂进行表征,结果表明,-NH_2与Co^(2+)有强络合作用,-COOH主要是静电作用,而-OH与钴离子没有相互作用。配位基团和Co^(2+)的相互作用,与HDS活性直接相关。配合物与Co^(2+)的结合可以有效生成Co-Mo-S活性相,且配合物碳化减弱载体与活性相的相互作用,有利于生成有更高本征活性的II型活性相。
The modified CoMo/r-Al203catalyst was prepared by addition of ethylene diamine(EN),ethanolamine(EA),ethylene glycol(EG)or malonic acid(MA).The effect of four bidentate molecules with different coordination groups on the dibenzothiophene HDS was compared.And the catalytic activity is determined in the sequence of CoMo(EN)>CoMo(EA)>CoMo(EG)~CoMo(MA)>CoMo.For all catalysts,the direct desulfurization route is dominated,but with the increase of reaction temperature,the desulfurization by hydrogenation route become more apparent.Chelating agents facilitate the HDS reaction through hydrogenation route.CoMo(EN)catalyst presents the highest hydrogenation ability.The catalysts were characterized by UV-vis,EA,XPS and HRTEM.The results show that NH2group has a strong complexing interaction with Co2+.COOH group mainly has an electrostatic interaction with cobalt ion.Meanwhile,OH group hardly interacts with Co2+.It is noted that the HDS activity is directly related to the interaction between coordinating groups and Co2+.The combination of coordinating molecules with Co2+leads to the effective formation of Co-Mo-S active center,and the carbonization of chelating decreases the interaction of the support with active phases,facilitating the formation of type II active phases which has a higher intrinsic catalytic activity.
作者
韩文鹏
张晔
李学宽
唐明兴
周立公
吴明红
葛晖
HAN Wen-peng;ZHANG Ye;LI Xue-kuan;TANG Ming-xing;ZHOU Li-gong;WU Ming-hong;GE Hui(College of Environment and Chemical Engineering, Shanghai University, Shanghai 200444, China;Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China)
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2017年第11期1332-1339,共8页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(21473231)
国家自然科学基金青年基金(21603256)资助~~
