高效稳定的MoS_(2)-TiO_(2)纳米复合催化剂用于浆态床菲催化加氢  

Highly active and stable MoS_(2)-TiO_(2)nanocomposite catalyst for slurry-phase phenanthrene hydrogenation

作　　者：杨成功 王冬娥[1] 黄蓉 韩健强 塔娜[3] 马怀军[1] 曲炜[1] 潘振栋[1] 王从新[1] 田志坚[1,3] Chenggong Yang;Donge Wang;Rong Huang;Jianqiang Han;Na Ta;Huaijun Ma;Wei Qu;Zhendong Pan;Congxin Wang;Zhijian Tian(Dalian National Laboratory for Clean Energy,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian116023,Liaoning,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian116023,Liaoning,China)

机构地区：[1]中国科学院大连化学物理研究所,洁净能源国家实验室,辽宁大连116023 [2]中国科学院大学,北京100049 [3]中国科学院大连化学物理研究所,催化基础国家重点实验室,辽宁大连116023

出　　处：《Chinese Journal of Catalysis》2023年第3期125-136,共12页催化学报（英文）

基　　金：新疆维吾尔自治区重点研发计划(2017B02007-1,2017B02007-2).

摘　　要：浆态床加氢是一种先进的非常规石油资源(重油等)加氢提质技术,它采用分散型催化剂以提高催化剂与原料中的沥青质等大分子的接触程度.沥青质等大分子中多环芳烃的快速转化是浆态床重油加氢技术的挑战,因此设计高活性的加氢催化剂是浆态床加氢技术的关键.作为典型的二维层状材料,分散型MoS_(2)催化剂表现出较好的催化加氢性能.然而,纳米尺寸的分散型MoS_(2)催化剂的稳定性有待提高,在高温高压下MoS_(2)片层会折叠并聚集成较大的颗粒以降低其表面能.MoS_(2)颗粒的生长会导致其悬浮性降低和边缘活性位点暴露量减少,因而降低催化剂的活性和寿命.因此,急需设计开发高性能的分散型MoS_(2)纳米催化剂,从而解决MoS_(2)层在高温高压条件下的折叠和聚集难题,提高MoS_(2)纳米催化剂的催化加氢活性和稳定性.纳米复合材料的构建可以有效地解决活性组分的团聚问题.近年来,Janus纳米复合材料因其在催化方面的广泛应用引起了科研人员的关注.此外,复合材料中各组分的种类对其催化活性有显著影响.早期研究表明,与Al_(2)O_(3),SiO_(2),MgO或其他金属氧化物相比,TiO_(2)复合MoS_(2)催化剂具有较高的催化加氢活性.本文通过一步溶剂热法合成了一系列不同MoS_(2)含量的Janus MoS_(2)-TiO_(2)纳米复合催化剂,并研究了其在浆态床催化菲加氢中的活性和稳定性.高分辨透射电镜结果表明,Janus MoS_(2)-TiO_(2)纳米复合催化剂由TiO_(2)纳米粒子(10-15 nm)和MoS_(2)片层(堆积层数为1-3和片层长度为2-10 nm)组成.活性位模型计算和NO化学吸附测试表明,与MoS_(2)和负载型MoS_(2)/TiO_(2)催化剂相比,Janus MoS_(2)-TiO_(2)纳米复合催化剂中的MoS_(2)层具有更高的MoS_(2)分散度,暴露出更多的边缘配位不饱和Mo原子.X射线光电子能谱结果表明,通过形成Mo-O-Ti键成功构建了具有强MoS_(2)-TiO_(2)相互作用的Janus结构,并出�MoS_(2)-TiO_(2)nanocomposite catalysts with Janus structure were synthesized via facile one-step solvothermal method.X-ray diffraction,high resolution transmission electron microscope,NO chemisorption and X-ray photoelectron spectroscopy were applied to characterize the composition and nanostructure of the MoS_(2)-TiO_(2)nanocomposite catalysts.Experimental results revealed that the MoS_(2)-TiO_(2)nanocomposite catalysts with Janus structure were composed of MoS_(2)layers(few stacked layers of 1-3 and short slabs of 2-10 nm)and TiO_(2)nanoparticles(10-15 nm),which have strong MoS_(2)-TiO_(2)interaction with transferring electrons from TiO_(2)to MoS_(2).Catalytic performance of MoS_(2)-TiO_(2)nanocomposite catalysts for phenanthrene hydrogenation was investigated and compared with that of MoS_(2)catalyst in an autoclave reactor with high temperature and high pressure.The phenanthrene conversion over the MoS_(2)-TiO_(2)nanocomposite catalyst with MoS_(2)content of 15.0 wt%(MoS_(2)-TiO_(2)-15)can reach 91.6%,which was much higher than 50.4%for MoS_(2)catalyst and 76.8%for conventional supported MoS_(2)/TiO_(2)-15 catalyst.After 7 cycles of phenanthrene hydrogenation reaction,the phenanthrene conversion over MoS_(2)-TiO_(2)-15 nanocatalyst remained at 68.6%,while the phenanthrene conversion over MoS_(2)catalyst was reduced to only 25.4%.The MoS_(2)-TiO_(2)nanocomposite catalysts exhibit significantly enhanced catalytic activity and stability for slurry phase hydrogenation.The enhanced catalytic activity originates from the exposure of abundant coordinatively unsaturated Mo atoms.The enhanced stability results from the Janus structure with stable MoS_(2)-TiO_(2)interaction and Mo-O-Ti bonds,which anchor MoS_(2)layers on the surface of TiO_(2)nanoparticles to avoid the curling,folding and agglomeration of MoS_(2)layers.This is an important finding on slurry phase catalytic hydrogenation performances of MoS_(2)-based nanocomposite catalysts with Janus structure.Shedding light on the research of Janus nanocomposite catal

关 键 词：纳米复合催化剂 高MoS_(2)分散度 配位不饱和Mo原子 MoS_(2)-TiO_(2)相互作用 催化加氢 

分 类 号：O643.36[理学—物理化学]