Interaction between Ni promoter and Al2O3 support and its effect on the performance of NiMo/γ-Al2O3 catalyst in hydrodesulphurization
-
摘要: 以γ-Al2O3为载体, 制备了一系列不同NiO负载量的NiMo/γ-Al2O3催化剂, 利用XRD、27Al-MAS NMR、Py-FTIR和HRTEM等技术对其进行了表征; 在高压微反装置对该系列催化剂的加氢脱硫性能进行了评价, 研究了助剂Ni与载体γ-Al2O3中不饱和铝间的相互作用及其对催化剂活性相结构形貌和催化活性的影响。结果表明, 助剂Ni优先作用于γ-Al2O3表面的四配位不饱和铝原子位置; 随着NiO负载量的增加, 硫化态NiMo/γ-Al2O3催化剂中MoS2活性相的长度变短、堆垛层数增加。Ni的引入能明显提高NiMo/γ-Al2O3催化剂的加氢脱硫活性, 但其加氢选择性则有所降低。Abstract: A series of NiMo/γ-Al2O3 catalysts with different NiO loadings were prepared and characterized by XRD, BET, 27Al-NMR, Py-IR and HRTEM. The activity of these NiMo/γ-Al2O3 catalysts in the hydrodesulphurization (HDS) of dibenzothiophene (DBT) was evaluated in a high pressure micro reactor; the interaction between Ni promoter and γ-Al2O3 support as well as its effect on the nanostructure of active MoS2 phase and HDS performance was then investigated. The results indicate that Ni promoter prefers to interact with the tetra-coordinated unsaturated aluminum sites on the support surface. With the increase of NiO loading, the average number of stacking layers for the MoS2 clusters in the sulfided NiMo/γ-Al2O3 catalysts is increased at the expense of the average length. As the slim MoS2 clusters are more active for the HDS of DBT, the addition of Ni promoter is then effective to enhance the catalytic activity of NiMo/γ-Al2O3 in HDS, but may lead to a slight decrease in the hydrogenation selectivity.
-
Key words:
- promoter /
- nickel /
- alumina /
- NiMo/γ-Al2O3 /
- active component /
- support /
- hydrodesulphurization
-
表 1 硫化态催化剂中MoS2的平均粒径及平均堆叠层数
Table 1 Length and layer stacking distribution of MoS2 crystallites in the sulfide NiMo/γ-Al2O3 catalysts with different NiO loadings
NiO loading w/% Average length L/nm Average stacked layer number 0 2.55 1.30 1.25 1.82 1.45 2.50 1.78 1.56 3.75 1.53 1.64 5.00 1.52 2.10 表 2 不同NiO负载量催化剂DBT加氢脱硫的产物分布及活性评价
Table 2 Products distribution for the hydrodesulfurization of dibenzothiophene over the NiMo/γ-Al2O3 catalysts with different NiO loadings
NiO loading w/% Product distribution /% xDBT/% sHYD/DDS/% BCH isomers CHB isomers BP 6H-DBT 4H-DBT DBT 0 0.000 0 10.02 27.88 0.433 1 1.187 1 60.38 38.01 0.40 1.25 0.207 3 10.17 37.39 0.300 7 1.530 8 50.40 47.77 0.32 2.50 0.65 12.87 50.28 0.194 1 1.056 7 30.94 67.81 0.28 3.75 0.48 18.56 78.55 0.000 0 0.045 4 2.36 97.59 0.24 5.00 0.24 12.63 85.82 0.000 0 0.000 0 1.30 98.70 0.15 -
[1] BOUWENS S M A M, VANZON F B M, VANDIJK M P, VANDERKRAAN A M, DEBEER V H G, VANVEEN J A R, KONINGSBERGER D C. On the structural differences between alumina-supported comos type Ⅰ and alumina-, silica-, and carbon-supported comos type Ⅱ phases studied by XAFS, MES, and XPS[J].J Catal, 1994, 146(2): 375. doi: 10.1006/jcat.1994.1076 [2] 尹海亮, 周同娜, 刘晨光.磷对NiMo/Al2O3催化剂活性组分与载体间相互作用的影响[J].石油炼制与化工, 2012, 7: 32-36. http://www.airitilibrary.com/Publication/alDetailedMesh?docid=sylzyhg201207007YIN Hai-liang, ZHOU Tong-na, LIU Chen-guang. Effect of phosphorus on the interaction between active component and support of NiMo/Al2O3catalyst [J]. Pet Process Petrochem, 2012, 7: 32-36. http://www.airitilibrary.com/Publication/alDetailedMesh?docid=sylzyhg201207007 [3] LAURITSEN J V, KIBSGAARD J, OLESEN G H, MOSES P G, HINNEMANN C, HELVEG S. Location and coordination of promoter atoms in Co-and Ni-promoted MoS2-based hydrotreating catalysts[J]. J Catal, 2007, 249: 220-233. doi: 10.1016/j.jcat.2007.04.013 [4] DIGNE M, SAUTET P, RAYBAUD P. Use of DFT to achieve a rational understanding of acid-basic properties of γ-alumina surfaces[J]. J Catal, 2004, 226(1): 54-68. doi: 10.1016/j.jcat.2004.04.020 [5] LIU X. DRIFTS study of surface of γ-alumina and its dehydroxylation[J]. J Phys Chem C, 2008, 112: 5066-5073. doi: 10.1021/jp711901s [6] OSTROMECKI M M, BURCHAM L J, WACHS I E, RAMANI N, EKERDT J E. The influence of metal oxide additives on the molecular structures of surface tungsten oxide species on alumina:Ⅰ.Ambient conditions[J]. J Mol Catal A: Chem, 1998, 132: 43-57. doi: 10.1016/S1381-1169(97)00226-4 [7] ZHAO C, YU Y, JENTYS A, LERCHER J A. Understanding the impact of aluminum oxide binder on Ni/HZSM-5 for phenol hydrodeoxygenation[J]. Appl Catal B: Environ, 2013, 132: 282-292. http://www.sciencedirect.com/science/article/pii/S0926337312005632 [8] BORELLO E, CIMINO A, GHIOTTI G, JACONO M L, SCHIAVELLO M, ZECCHINA A. Surface configurations and infra-red studies on nickel oxide supported on η-and γ-Al2O3[J]. Discuss Faraday Soc, 1971, 52: 149-160. doi: 10.1039/DF9715200149 [9] SUN Y, YUAN L, MA S, HAN Y, ZHAO L, WANG W. Improved catalytic activity and stability of mesostructured sulfated zirconia by Al promoter[J]. Appl Catal A: Gen, 2004, 268(1/2): 17-24. http://d.wanfangdata.com.cn/NSTLQK_NSTL_QKJJ026119586.aspx [10] MORTERRA C, COLUCCIA S, CHIRINO A, BOCCUZZI F.Infrared study of the adsorption of pyridine on α-Al2O3[J]. J Catal, 1978, 54(3): 348-364. doi: 10.1016/0021-9517(78)90083-0 [11] HENSEN E J M, KOOYMAN P J, VAN DER MEER Y, DE BEER V H J, VAN VEEN J A R, VAN SANTEN R A. The relation between morphology and hydrotreating activity for supported MoS2 particles[J]. J Catal, 2001, 199(2): 224-235. doi: 10.1006/jcat.2000.3158 [12] SUN M, KOOYMAN P J, PRINS R. A high-resolution transmission electron microscopy study of the influence of fluorine on the morphology and dispersion of WS2 in sulfided W/Al2O3 and NiW/Al2O3 catalysts[J]. J Catal, 2002, 206(2): 368-375. doi: 10.1006/jcat.2001.3503 [13] ALONSO G, BERHAULT G, AGUILAR A, COLLINS V, ORNELAS C, FUENTES S, CHIANELLI R R. Characterization and HDS activity of mesoporous MoS2 catalysts prepared by in situ activation of tetraalkylammonium thiomolybdates[J]. J Catal, 2002, 208(2): 359-369. doi: 10.1006/jcat.2002.3553 [14] NIKULSHIN P A, SALNIKOV V A, MOZHAEV A V, MINAEV P P, KOGAN V M, PIMERZIN A A. Relationship between active phase morphology and catalytic properties of the carbon-alumina-supported Co (Ni) Mo catalysts in HDS and HYD reactions[J]. J Catal, 2014, 309: 386-396. doi: 10.1016/j.jcat.2013.10.020 [15] TUXEN A, KIBSGAARD J, GØBEL H. Size threshold in the dibenzothiophene adsorption on MoS2 nanoclusters[J]. ACS nano, 2010, 4(8): 4677-4682. doi: 10.1021/nn1011013 [16] TUXEN A K, FÜCHTBAUER H G, TEMEL B, HINNEMANN B, TOPSØE H, KNUDSEN K, BESENBACHER F, LAURITSEN J V. Atomic-scale insight into adsorption of sterically hindered dibenzothiophenes on MoS2 and Co-Mo-S hydrotreating catalysts[J]. J Catal, 2012, 295: 146-154. doi: 10.1016/j.jcat.2012.08.004 [17] BESENBACHER F, BRORSON M, CLAUSEN B S, HELVEG S, HINNEMANN B, KIBSGAARD J, LAURITSEN J V. Recent STM, DFT and HAADF-STEM studies of sulfide-based hydrotreating catalysts: Insight into mechanistic, structural and particle size effects[J]. Catal Today, 2008, 130(1): 86-96. doi: 10.1016/j.cattod.2007.08.009 [18] HENSEN E J M, KOOYMAN P J, VAN DER MEER Y, ET A L. The relation between morphology and hydrotreating activity for supported MoS2 particles[J]. J Catal, 2001, 199(2): 224-235. doi: 10.1006/jcat.2000.3158 [19] SHIMADA H. Morphology and orientation of MoS2 clusters on Al2O3 and TiO2 supports and their effect on catalytic performance[J]. Catal Today, 2003, 86(1): 17-29. http://www.sciencedirect.com/science/article/pii/S0920586103004012