绿色合成介孔碳负载(Ni)MoS_(2)加氢脱硫催化剂

Green synthesis of mesoporous carbon supported(Ni)MoS_(2) as efficient hydrodesulfurization catalyst

以Anderson结构Ni-Mo杂多酸簇(NH_(4))_(4)[NiMo_(6)O_(24)H_(6)]·5H_(2)O、硫脲、柠檬酸、氯化钠为原料,采用冻干法得到前驱体后焙烧、洗涤得到介孔碳骨架负载(Ni)MoS_(2)纳米颗粒的加氢脱硫催化剂,考察了其对二苯并噻吩的加氢脱硫活性,并采用X射线衍射、N2低温吸附-脱附、拉曼光谱、X光电子能谱、扫描电子显微镜、高分辨透射电镜、程序升温还原等表征手段对催化剂进行了分析。结果表明,介孔碳骨架负载(Ni)MoS_(2)纳米颗粒催化剂具有较弱的载体-金属相互作用,MoS_(2)纳米颗粒平均长度较短(4.9 nm),层数适宜(4.8),NiMoS活性相含量较高,二苯并噻吩的转化率可达94.1%,反应速率常数及活性位转换频率分别可达1.7×10^(–6)mol/(g·s)和2.8×10^(–3)s^(–1)。该方法利用原位生成的氯化钠晶体及硫化氢气体分别作为介孔模板剂和硫化剂,实现了介孔碳载体与(Ni)MoS_(2)纳米颗粒的同步合成及锚定,并为加氢脱硫催化剂的绿色制备提供了新的思路。

Mesoporous carbon supported Ni-Mo hydrodesulfurization(HDS)catalysts have been successfully prepared with Anderson polyoxometalate(NH_(4))_(4)[NiMo_(6)O_(24)H_(6)]·5H_(2)O,thiourea,citric acid,and sodium chloride to evaluate the HDS performance with dibenzothiophene.The catalysts were prepared by one-step vacuum freezedrying,followed by calcination under nitrogen and washing off the template,and then structurally characterized via many devices,including XRD,Raman,low temperature N_(2)adsorption-desorption isotherm,SEM,HRTEM,XPS,and TPR.The results show these catalysts possess weaker metal-support interaction,shorter MoS_(2)particles(4.9 nm)and appropriate stacking number(4.8),and higher percent of NiMoS active phase.The dibenzothiophene conversion,overall pseudo-first order rate constant and the turnover frequency can reach 94.1%,1.7×10^(–6)mol/(g·s)and 2.8×10^(–3)s^(–1),respectively.By using in-situ formed NaCl and H_(2)S as hard template and sulfidizing agent respectively,this methodology opens a new avenue for the simple and environmental friendly fabrication of HDS catalysts via the synchronization and riveting of mesoporous carbon support and MoS_(2)particles.