| H2在Mo x S y 团簇上吸附解离的尺寸效应研究 |
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| 引用本文： | 杜峰,尹思琦,罗辉,邓文安,李传,黄振薇,王文静.H2在Mo x S y 团簇上吸附解离的尺寸效应研究[J].化工学报,2022,73(9):3895-3903. |
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| 作者姓名： | 杜峰 尹思琦 罗辉 邓文安 李传 黄振薇 王文静 |
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| 作者单位： | 中国石油大学（华东）重质油国家重点实验室，山东 青岛 266580 |
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| 基金项目： | 国家自然科学基金项目(22078365) |
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| 摘 要： | 浆态床加氢工艺可以处理不同来源的劣质重油、渣油，氢气的活化是重油加氢处理过程中发生的主要反应之一。钼基催化剂的分散性是影响重油加氢活性的关键因素。构建了Mo7S15、Mo12S26、Mo18S39、Mo25S54和Mo33S71团簇，利用密度泛函理论研究了团簇自身的稳定性、活性以及H2在不同尺寸团簇上的吸附与解离过程。结果发现，在目前所建立的团簇中，其尺寸越小，结合能越低，最高占据分子轨道-最低未占分子轨道(HOMO-LUMO)能隙值越小，团簇稳定性越弱，活性越强。H2在簇上的稳定吸附位点为边缘位点。随团簇尺寸增大，吸附能分别为-64.25、-34.60、-34.14、-7.20、-6.82 kJ/mol，吸附能绝对值减小，氢气分子与团簇的相互作用减弱，并且解离能逐渐增大，分别为13.76、33.14、53.64、60.75、64.47 kJ/mol。目前的结果表明，团簇尺寸越小，氢气的吸附解离越容易，显示出更高的活性。
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| 关 键 词： | Mo x S y 团簇 团簇尺寸 氢气活化 钼基催化剂 密度泛函理论 |
| 收稿时间： | 2022-04-15 |
Study on size effect of H2 adsorption and dissociation on Mo x S y clusters |
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| Feng DU,Siqi YIN,Hui LUO,Wenan DENG,Chuan LI,Zhenwei HUANG,Wenjing WANG.Study on size effect of H2 adsorption and dissociation on Mo x S y clusters[J].Journal of Chemical Industry and Engineering(China),2022,73(9):3895-3903. |
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| Authors: | Feng DU Siqi YIN Hui LUO Wenan DENG Chuan LI Zhenwei HUANG Wenjing WANG |
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| Affiliation: | State Key Laboratory of Heavy Oil, China University of Petroleum, Qingdao 266580, Shandong, China |
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| Abstract: | Slurry bed hydrotreating process can treat inferior heavy oil and residual oil from different sources. Therefore, compared with other processes, the process is characterized by strong adaptability of raw materials. One of the main reactions of heavy oil hydrotreating is the activation of hydrogen. Molybdenum-based dispersed catalyst is widely used as an efficient hydrogenation catalyst in the slurry bed hydrogenation process. One of the key factors affecting the hydrogenation activity of heavy oil is the dispersion of molybdenum-based catalysts. Therefore, it is meaningful to explore the dispersion of the catalyst for hydrogen activation. In this paper, Mo7S15, Mo12S26, Mo18S39, Mo25S54 and Mo33S71 clusters were built and their structure is optimized. On the basis of stable structure, the stability and activity of clusters with different sizes were studied, and the adsorption dissociation process of hydrogen on Mo x S y clusters with different sizes was discussed, including the stability of hydrogen molecules at different adsorption sites, the adsorption dissociation process of hydrogen molecules on Mo x S y clusters with different sizes, and the changes with the size of Mo x S y clusters. According to the calculation results, it is found that the currently established clusters with smaller size have the lower binding energy, the smaller HOMO-LUMO energy gap value, the weaker stability and the stronger activity. During the adsorption and dissociation of H2 above the cluster, it is found that hydrogen is more easily adsorbed at the edge position. With the increase of cluster size, the adsorption energy was -64.25, -34.60, -34.14, -7.20 and -6.82 kJ/mol; the absolute value of the adsorption energy decreased; the interaction between hydrogen molecules and the cluster was weaker; the dissociation energy gradually increased, and were 13.76, 33.14, 53.64, 60.75 and 64.47 kJ/mol, respectively. The current results show that the smaller the cluster size, the easier it is for hydrogen to adsorb/ dissociate and the cluster shows higher activity. |
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| Keywords: | Mo x S y cluster cluster size hydrogen activation Mo-based catalyst density functional theory |
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