Propane dehydrogenation is an important route for propylene production. Among various non-noble metal catalytic systems, VOx-based catalysts have attracted considerable attention owing to their excellent dehydrogenation activity, high selectivity, and relatively low cost. Nevertheless, the practical application of VOx catalysts is still limited by rapid deactivation caused by coke deposition. The coke formation rate is linearly correlated with the polymerization degree of surface vanadium species. In this work, a series of VOx/Al2O3 catalysts with different VOx polymerization degrees were constructed by regulating the content of penta-coordinated aluminum sites (AlV) in Al2O3 supports. The Al2O3 supports were synthesized via urea-assisted hydrothermal crystallization of pseudo-boehmite followed by calcination, with the AlV content (5.52 %-19.60 %) tuned by adjusting the synthesis conditions. The effect of AlV sites on the structural evolution of VOx species and propane dehydrogenation performance was systematically studied. The obtained samples were characterized by 27Al MAS NMR, XRD, UV-vis, Raman, H2-TPR and NH3-TPD, and the catalytic performance was evaluated in a fixed-bed reactor at 550 ℃. Coke deposition and propylene adsorption-desorption behaviors were further investigated by thermogravimetric analysis, C3H8-DRIFTS and C3H6-DRIFTS. Results showed that, with increasing AlV content in the Al2O3 support, the surface vanadium species gradually transformed from highly polymerized VOx species to low-polymerized VOx species and further toward isolated species. As the AlV content increased from 5.52 % to 19.60 %, the apparent band gap increased almost linearly from 2.44 to 2.84 eV. Meanwhile, highly polymerized VOx decreased from 21.20 % to be below the detection limit, and low-polymerized VOx content reached a maximum of 84.74 %. This indicated that AlV sites played an important role in tuning the dispersion state and polymerization degree of vanadium oxide species on alumina. Correlation analysis revealed that the low-polymerized VOx species was positively correlated with propylene selectivity and negatively correlated with the deactivation rate constant. When low-polymerized VOx exceeded 80 %, propylene selectivity surpassed 98.4 % and the deactivation rate constant fell below 0.075 h⁻¹. This fraction can thus serve as a quantitative descriptor for catalyst design. Among the prepared catalysts, the VOx/Al2O3 catalyst containing 11.26 % of AlV possessed the highest percentage of low-polymerized VOx species. It exhibited the best performance in propane dehydrogenation, with a propane conversion of 15.0 %, a propylene selectivity of 98.5 %, and a propylene space-time yield of 2.8 mmol·gcat-1·h-1. Its stability was also significantly higher than that of the catalyst supported on commercial alumina. This study confirmed that AlV sites promote the formation of low-polymerized VOx species, which acted as the dominant active species for propane dehydrogenation. Mechanistic studies demonstrated that low-polymerized VOx possesses moderate surface acidity and facilitate propylene desorption. The enrichment of low-polymerized VOx species enhanced the propylene formation rate while suppressing deep dehydrogenation and coke formation, and ultimately improving catalyst stability. This study provided a feasible strategy for optimizing VOx/Al2O3 catalysts, achieving by regulating coordination environment of Al species in Al2O3 supports. It also offered guidance for designing efficient and stable non-noble metal catalysts for propane dehydrogenation.
[1] Carrero C. A.; Schloegl R.; Wachs I. E.; Schomaecker R. ACS Catal.2014, 4, 3357.
[2] Sattler J. J. H. B.; Ruiz-Martinez J.; Santillan-Jimenez E.; Weckhuysen, B. M. Chem. Rev.2014, 114, 10613.
[3] Lavrenov A. V.; Saifulina L. F.; Buluchevskii E. A.; Bogdanets, E. N. Catal. Ind.2015, 7, 175.
[4] Wang T.; Yang L.-B.; Bu T.-T.; Sun S.-L.; Zhou J.-B.; Dong B.-L.; Wang, L.-F. Low-Carbon Chem. Chem. Eng.2026, 51, 103 (in Chinese).
(王甜, 杨利斌, 卜婷婷, 孙世林, 周金波, 董炳利, 王洛飞. 低碳化学与化工, 2026, 51, 103.)
[5] Sokolov S.; Stoyanova M.; Rodemerck U.; Linke D.; Kondratenko, E. V. J. Catal.2012, 293, 67.
[6] Wang Y.-S.; Liu G.-Z.; Yu, H.-B. Inorg. Chem. Ind.2023, 55, 1 (in Chinese).
(王延苏, 刘国柱, 于海斌. 无机盐工业, 2023, 55, 1.)
[7] Hong X.-S.; Wu X.; Song L.; Miao C.-X.; Yang, W.-M. Chem. Ind. Eng. Prog.2024, 43, 5517 (in Chinese).
(洪学思, 吴省, 宋磊, 缪长喜, 杨为民. 化工进展, 2024, 43, 5517.)
[8] Harlin M. E.; Niemi V. M.; Krause, A. O. I. J. Catal.2000, 195, 67.
[9] Jackson S. D.; Rugmini S.; Stair P. C.; Wu, Z. Chem. Eng. J.2006, 120, 127.
[10] Harlin M. E.; Niemi V. M.; Krause A. O. I.; Weckhuysen, B. M. J. Catal.2001, 203, 242.
[11] Sokolov S.; Stoyanova M.; Rodemerck U.; Linke D.; Kondratenko, E. V. Catal. Sci. Technol.2014, 4, 1323.
[12] Sokolov S.; Bychkov V. Y.; Stoyanova M.; Rodemerck U.; Bentrup U.; Linke D.; Tyulenin Y. P.; Korchak V. N.; Kondratenko E. V. ChemCatChem2015, 7, 1691.
[13] Zhao Z.-J.; Wu T.; Xiong C.; Sun G.; Mu R.; Zeng L.; Gong, J. Angew. Chem. Int. Ed.2018, 57, 6791.
[14] Hu P.; Lang W.-Z.; Yan X.; Chu L.-F.; Guo Y.-J. J. Catal.2018, 358, 108.
[15] Bai P.; Ma Z.; Li T.; Tian Y.; Zhang Z.; Zhong Z.; Xing W.; Wu P.; Liu X.; Yan, Z. ACS Appl. Mater. Interfaces2016, 8, 25979.
[16] Li Y.; Yu X.; Zhang Q.; Kondratenko V. A.; Wang Y.; Cui G.; Zhou M.; Xu C.; Kondratenko E. V.; Jiang G. J. Catal.2022, 413, 658.
[17] Liu G.; Zhao Z.-J.; Wu T.; Zeng L.; Gong J. ACS Catal.2016, 6, 5207.
[18] Tian Y.-P.; Bai P.; Liu S.-M.; Liu X.-M.; Yan, Z.-F. Fuel Process. Technol.2016, 151, 31.
[19] Gu Y.; Liu H.; Yang M.; Ma Z.; Zhao L.; Xing W.; Wu P.; Liu X.; Mintova S.; Bai P.; Yan, Z. Appl. Catal. B: Environ.2020, 274, 119089.
[20] Bai P.; Yang M.; Chen X.; Liu Y.; Yang W.; Zhao L.; Wu P.; Wang C.; Mintova S.; Yan Z. Catal. Today2022, 402, 248.
[21] Shan Y.-L.; Zhao W.-T.; Zhao S.-L.; Wang X.-X.; Sun H.-L.; Yu W.-L.; Ding J.-W.; Feng X.; Chen D. Mol. Catal.2021, 504, 111466.
[22] Gao X.-Q.; Song W.; Li W.-C.; Lu, A.-H. Catal. Sci. Technol.2021, 11, 2597.
[23] Yang X.; Li Q.; Lu E.; Wang Z.; Gong X.; Yu Z.; Guo Y.; Wang L.; Guo Y.; Zhan W.; Zhang J.; Dai S. Nat. Commun.2019, 10, 1611.
[24] Wu M.; Li W.; Zhang X.; Xue F.; Yang T.; Yuan L. ChemCatChem2021, 13, 3490.
[25] Zhao Z.-X.Ph.D. China University of Petroleum (East China), Qingdao, 2024 (in Chinese).
(赵振祥,博士论文,中国石油大学(华东),青岛,2024)
[26] Yuan Q.; Yin A.-X.; Luo C.; Sun L.-D.; Zhang Y.-W.; Duan W.-T.; Liu H.-C.; Yan, C.-H. J. Am. Chem. Soc.2008, 130, 3465.
[27] Thommes M.; Kaneko K.; Neimark A. V.; Olivier J. P.; Rodriguez-Reinoso F.; Rouquerol J.; Sing, K. S. W. Pure Appl. Chem.2015, 87, 1051.
[28] Weckhuysen B. M.; Keller, D. E. Catal. Today2003, 78, 25.
[29] Wu Z.; Kim H.-S.; Stair P. C.; Rugmini S.; Jackson, S. D. J. Phys. Chem. B2005, 109, 2793.
[30] Concepción P.; Navarro M. T.; Blasco T.; López Nieto J. M.; Panzacchi B.; Rey F. Catal. Today2004, 96, 179.
[31] Hu P.; Lang W.-Z.; Yan X.; Chen X.-F.; Guo, Y.-J. Appl. Catal. A: Gen.2018, 553, 65.
[32] Rodemerck U.; Stoyanova M.; Kondratenko E. V.; Linke D. J. Catal.2017, 352, 256.
[33] Khodakov A.; Yang J.; Su S.; Iglesia E.; Bell, A. T. J. Catal.1998, 177, 343.
[34] Wang C.-B.; Deo G.; Wachs, I. E. J. Catal.1998, 178, 640.
[35] Elbadawi A. H.; Ba-Shammakh M. S.; Al-Ghamdi S.; Razzak S. A.; Hossain, M. M. Chem. Eng. J.2016, 284, 448.
[36] Stobbe-Kreemers A. W.; van Leerdam G. C.; Jacobs J. P.; Brongersma H. H.; Scholten, J. J. F. J. Catal.1995, 152, 130.
[37] Bautista F. M.; Campelo J. M.; Luna D.; Luque J.; Marinas, J. M. Catal. Today2007, 128, 183.
[38] Arena F.; Frusteri F.; Martra G.; Coluccia S.; Parmaliana, A. J. Chem. Soc., Faraday Trans.1997, 93, 3849.
[39] Xiong C.; Chen S.; Yang P.; Zha S.; Zhao Z.-J.; Gong J. ACS Catal.2019, 9, 5816.
[40] Zhang X.-L.; Huang Y.; Dou Y. Spec. Petrochem.2025, 42, 57 (in Chinese).
(张晓磊, 黄意, 窦岩. 精细石油化工, 2025, 42, 57.)
[41] Chen S.; Qin Z.; Xu X.; Wang, J. Appl. Catal. A: Gen.2006, 302, 185.
[42] Rostom S.; de Lasa, H. Ind. Eng. Chem. Res.2017, 56, 13109.
[43] Greensfelder B. S.; Voge H. H.; Good, G. M. Ind. Eng. Chem.1949, 41, 2573.
[44] Amusa H. K.; Kekere-Ekun M.; Alabi S.; Adeniyi A. G.; Arjah A. S.; Al-Bogami S. A.; Al-Ghamdi S.; Hossain, M. M. Appl. Catal. A: Gen.2026, 720, 120946.
[45] Li C.; Vidal-Moya A.; Miguel P. J.; Dedecek J.; Boronat M.; Corma A. ACS Catal.2018, 8, 7688.
[46] Zhang W.; Wang H.; Jiang J.; Sui Z.; Zhu Y.; Chen D.; Zhou X. ACS Catal.2020, 10, 12932.
[47] Wu T.; Liu G.; Zeng L.; Sun G.; Chen S.; Mu R.; Gbonfoun S. A.; Zhao Z.-J.; Gong J. AIChE J.2017, 63, 4911.
[48] Valcárcel A.; Ricart J. M.; Clotet A.; Illas F.; Markovits A.; Minot C. J. Catal.2006, 241, 115.
[49] Karge H. G.; Boldingh, E. P. Catal. Today1988, 3, 53.
[50] Eisenbach D.; Gallei E. J. Catal.1979, 56, 377.
[51] Sun G.; Zhao Z.-J.; Mu R.; Zha S.; Li L.; Chen S.; Zang K.; Luo J.; Li Z.; Purdy S. C.; Kropf A. J.; Miller J. T.; Zeng L.; Gong J. Nat. Commun.2018, 9, 4454.
[52] Waleska P. S.; Hess, C. J. Phys. Chem. C2016, 120, 18510.
[53] Bai P.; Zhao Z.; Nan T.; Yang J.; Xue Y.; Wang C.; Lu S.; Wu H.; Wang G.; Zhong Z.; Wu P.; Wang C.; Pang C.; Pang Q.; Mintova S.; Yan, Z. Chem. Eng. J.2024, 498, 155220.
