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Identification of the catalytically active sites emerges as the prerequisite for an atomic-level comprehensive understanding and further rational design of highly efficient catalysts. Here, we demonstrate a kinetics strategy to identify the active sites of Au catalyst for the disentanglement of geometric and electronic effects on the selective oxidation of propylene to acrolein. Both the Ti-containing titanium-silicalite-1 (TS-1) and Ti-free silicalite-1 (S-1) were employed as supports to immobilize Au catalysts, which were investigated by a combination of multiple characterization, kinetics analysis, and crystal structure modelling. The Au (111) sites are identified as the main active site for acrolein formation, while their electronic effects are highly relevant to the presence or absence of Ti. Moreover, propylene epoxide (PO) formation mainly involves the co-participation of Au and Ti sites, and the proximity between Au and Ti sites is found to have less influences on PO formation in a certain distance. In comparison, acrolein is very likely to generate over Au (111) sites via the hydrogen-assisted O2 activation to oxygenated species for its oxidizing propylene. The insights gained here could guide the design and preparation of Au catalysts for selective propylene oxidation.


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Kinetics and mechanistic insights into the active sites of Au catalysts for selective propylene oxidation

Show Author's information Qianhong Wang§Zhihua Zhang§Keng SangWenyao Chen( )Gang QianJing ZhangXinggui ZhouXuezhi Duan( )
State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China

§ Qianhong Wang and Zhihua Zhang contributed equally to this work.

Abstract

Identification of the catalytically active sites emerges as the prerequisite for an atomic-level comprehensive understanding and further rational design of highly efficient catalysts. Here, we demonstrate a kinetics strategy to identify the active sites of Au catalyst for the disentanglement of geometric and electronic effects on the selective oxidation of propylene to acrolein. Both the Ti-containing titanium-silicalite-1 (TS-1) and Ti-free silicalite-1 (S-1) were employed as supports to immobilize Au catalysts, which were investigated by a combination of multiple characterization, kinetics analysis, and crystal structure modelling. The Au (111) sites are identified as the main active site for acrolein formation, while their electronic effects are highly relevant to the presence or absence of Ti. Moreover, propylene epoxide (PO) formation mainly involves the co-participation of Au and Ti sites, and the proximity between Au and Ti sites is found to have less influences on PO formation in a certain distance. In comparison, acrolein is very likely to generate over Au (111) sites via the hydrogen-assisted O2 activation to oxygenated species for its oxidizing propylene. The insights gained here could guide the design and preparation of Au catalysts for selective propylene oxidation.

Keywords: Au catalysts, active site, propylene oxidation, geometric and electronic effects, Au-Ti proximity

References(36)

[1]
Sienel, G.; Rieth, R.; Rowbottom, K. T. Epoxides. In Ullmann’s Encyclopedia of Industrial Chemistry. Wiley-VCH: Weinheim, 2000.
[2]

Hayashi, T.; Tanaka, K.; Haruta, M. Selective vapor-phase epoxidation of propylene over Au/TiO2 catalysts in the presence of oxygen and hydrogen. J. Catal. 1998, 178, 566–575.

[3]

Sinha, A. K.; Seelan, S.; Tsubota, S.; Haruta, M. A three-dimensional mesoporous titanosilicate support for gold nanoparticles: Vapor-phase epoxidation of propene with high conversion. Angew. Chem., Int. Ed. 2004, 43, 1546–1548.

[4]

Chowdhury, B.; Bravo-Suárez, J. J.; Daté, M.; Tsubota, S.; Haruta, M. Trimethylamine as a gas-phase promoter: Highly efficient epoxidation of propylene over supported gold catalysts. Angew. Chem., Int. Ed. 2006, 45, 412–415.

[5]

Bravo-Suárez, J. J.; Bando, K. K.; Lu, J. Q.; Haruta, M.; Fujitani, T.; Oyama, T. Transient technique for identification of true reaction intermediates: Hydroperoxide species in propylene epoxidation on gold/titanosilicate catalysts by X-ray absorption fine structure spectroscopy. J. Phys. Chem. C 2008, 112, 1115–1123.

[6]

Chowdhury, B.; Bravo-Suárez, J. J.; Mimura, N.; Lu, J. Q.; Bando, K. K.; Tsubota, S.; Haruta, M. In situ UV–vis and EPR study on the formation of hydroperoxide species during direct gas phase propylene epoxidation over Au/Ti-SiO2 catalyst. J. Phys. Chem. B 2006, 110, 22995–22999.

[7]

Stangland, E. E.; Stavens, K. B.; Andres, R. P.; Delgass, W. N. Characterization of gold-titania catalysts via oxidation of propylene to propylene oxide. J. Catal. 2000, 191, 332–347.

[8]

Ji, J. J.; Lu, Z.; Lei, Y.; Turner, C. H. Theoretical studies on the direct propylene epoxidation using gold-based catalysts: A mini-review. Catalysts 2018, 8, 421.

[9]

Moskaleva, L. V. Theoretical mechanistic insights into propylene epoxidation on Au-based catalysts: Surface O versus OOH as oxidizing agents. Catal. Today 2016, 278, 45–55.

[10]

Ji, J. J.; Lu, Z.; Lei, Y.; Turner, C. H. Mechanistic insights into the direct propylene epoxidation using Au nanoparticles dispersed on TiO2/SiO2. Chem. Eng. Sci. 2018, 191, 169–182.

[11]

Dai, Y. M.; Chen, Z. J.; Guo, Y. L.; Lu, G. Z.; Zhao, Y. F.; Wang, H. F.; Hu, P. Significant enhancement of the selectivity of propylene epoxidation for propylene oxide: A molecular oxygen mechanism. Phys. Chem. Chem. Phys. 2017, 19, 25129–25139.

[12]

Ma, Z.; Dai, S. Development of novel supported gold catalysts: A materials perspective. Nano Res. 2011, 4, 3–32.

[13]

He, C.; Wu, Q. J.; Mao, M. J.; Zou, Y. H.; Liu, B. T.; Huang, Y. B.; Cao, R. Multifunctional gold nanoparticles@imidazolium-based cationic covalent triazine frameworks for efficient tandem reactions. CCS Chem. 2021, 3, 2368–2380.

[14]

Lee, W. S.; Lai, L. C.; Akatay, M. C.; Stach, E. A.; Ribeiro, F. H.; Delgass, W. N. Probing the gold active sites in Au/TS-1 for gas-phase epoxidation of propylene in the presence of hydrogen and oxygen. J. Catal. 2012, 296, 31–42.

[15]

Qi, C. X.; Huang, J. H.; Bao, S. Q.; Su, H. J.; Akita, T.; Haruta, M. Switching of reactions between hydrogenation and epoxidation of propene over Au/Ti-based oxides in the presence of H2 and O2. J. Catal. 2011, 281, 12–20.

[16]

Wang, G.; Cao, Y. Q.; Zhang, Z. H.; Xu, J. L.; Lu, M. K.; Qian, G.; Duan, X. Z.; Yuan, W. K.; Zhou, X. G. Surface engineering and kinetics behaviors of Au/uncalcined TS-1 catalysts for propylene epoxidation with H2 and O2. Ind. Eng. Chem. Res. 2019, 58, 17300–17307.

[17]

Wang, G.; Du, W.; Duan, X. Z.; Cao, Y. Q.; Zhang, Z. H.; Xu, J. L.; Chen, W. Y.; Qian, G.; Yuan, W. K.; Zhou, X. G. et al. Mechanism-guided elaboration of ternary Au-Ti-Si sites to boost propylene oxide formation. Chem. Catalysis 2021, 1, 885–895.

[18]

Lu, X. N.; Zhao, G. F.; Lu, Y. Propylene epoxidation with O2 and H2: A high-performance Au/TS-1 catalyst prepared via a deposition–precipitation method using urea. Catal. Sci. Technol. 2013, 3, 2906–2909.

[19]

Feng, X.; Sheng, N.; Liu, Y. B.; Chen, X. B.; Chen, D.; Yang, C. H.; Zhou, X. G. Simultaneously enhanced stability and selectivity for propene epoxidation with H2 and O2 on Au catalysts supported on nano-crystalline mesoporous TS-1. ACS Catal. 2017, 7, 2668–2675.

[20]

Feng, X.; Song, Z. N.; Liu, Y. B.; Chen, X. B.; Jin, X.; Yan, W. J.; Yang, C. H.; Luo, J.; Zhou, X. G.; Chen, D. Manipulating gold spatial location on titanium silicalite-1 to enhance the catalytic performance for direct propene epoxidation with H2 and O2. ACS Catal. 2018, 8, 10649–10657.

[21]

Millini, R.; Perego, G.; Berti, D.; Parker, W. O. Jr.; Carati, A.; Bellussi, G. Structural characterization of as-synthesized B- and Ti-containing MFI-type molecular sieves. Microporous Mesoporous Mater. 2000, 35–36, 387–403.

[22]

Güntner, A. T.; Pineau, N. J.; Chie, D.; Krumeich, F.; Pratsinis, S. E. Selective sensing of isoprene by Ti-doped ZnO for breath diagnostics. J. Mater. Chem. B 2016, 4, 5358–5366.

[23]

Feng, X.; Duan, X. Z.; Qian, G.; Zhou, X. G.; Chen, D.; Yuan, W. K. Au nanoparticles deposited on the external surfaces of TS-1: Enhanced stability and activity for direct propylene epoxidation with H2 and O2. Appl. Catal. B: Environ. 2014, 150–151, 396–401.

[24]

Zhang, Z. H.; Zhao, X.; Wang, G.; Xu, J. L.; Lu, M. K.; Tang, Y. Q.; Fu, W. Z.; Duan, X. Z.; Qian, G.; Chen, D. et al. Uncalcined TS-2 immobilized Au nanoparticles as a bifunctional catalyst to boost direct propylene epoxidation with H2 and O2. AIChE J. 2020, 66, e16815.

[25]

Haghighi, S. K.; Kharat, A. N. Selective propylene epoxidation by low cost microporous/mesoporous hierarchical titanium silicalite-1. Inorg. Chem. Commun. 2021, 125, 108413.

[26]

Feng, X.; Duan, X. Z.; Qian, G.; Zhou, X. G.; Chen, D.; Yuan, W. K. Insights into size-dependent activity and active sites of Au nanoparticles supported on TS-1 for propene epoxidation with H2 and O2. J. Catal. 2014, 317, 99–104.

[27]

Shekhar, M.; Wang, J.; Lee, W. S.; Williams, W. D.; Kim, S. M.; Stach, E. A.; Miller, J. T.; Delgass, W. N.; Ribeiro, F. H. Size and support effects for the water–gas shift catalysis over gold nanoparticles supported on model Al2O3 and TiO2. J. Am. Chem. Soc. 2012, 134, 4700–4708.

[28]

Feng, X.; Yang, J.; Duan, X. Z.; Cao, Y. Q.; Chen, B. X.; Chen, W. Y.; Lin, D.; Qian, G.; Chen, D.; Yang, C. H. et al. Enhanced catalytic performance for propene epoxidation with H2 and O2 over bimetallic Au-Ag/uncalcined titanium silicate-1 catalysts. ACS Catal. 2018, 8, 7799–7808.

[29]

Huo, Z. Y.; Tsung, C. K.; Huang, W. Y.; Zhang, X. F.; Yang, P. D. Sub-two nanometer single crystal Au nanowires. Nano Lett. 2008, 8, 2041–2044.

[30]

Zhou, K.; Wang, W.; Zhao, Z.; Luo, G. H.; Miller, J. T.; Wong, M. S.; Wei, F. Synergistic gold-bismuth catalysis for non-mercury hydrochlorination of acetylene to vinyl chloride monomer. ACS Catal. 2014, 4, 3112–3116.

[31]

Liu, X.; Conte, M.; Elias, D.; Lu, L.; Morgan, D. J.; Freakley, S. J.; Johnston, P.; Kiely, C. J.; Hutchings, G. J. Investigation of the active species in the carbon-supported gold catalyst for acetylene hydrochlorination. Catal. Sci. Technol. 2016, 6, 5144–5153.

[32]

Dong, C. Y.; Li, Y. L.; Cheng, D. Y.; Zhang, M. T.; Liu, J. J.; Wang, Y. G.; Xiao, D. Q.; Ma, D. Supported metal clusters: Fabrication and application in heterogeneous catalysis. ACS Catal. 2020, 10, 11011–11045.

[33]

Qian, K.; Luo, L. F.; Bao, H. Z.; Hua, Q.; Jiang, Z. Q.; Huang, W. X. Catalytically active structures of SiO2-supported Au nanoparticles in low-temperature CO oxidation. Catal. Sci. Technol. 2013, 3, 679–687.

[34]

Liu, X. Y.; Friend, C. M. Competing epoxidation and allylic hydrogen activation: Trans-β-methylstyrene oxidation on Au (111). J. Phys. Chem. C 2010, 114, 5141–5147.

[35]

Deng, X. Y.; Min, B. K.; Liu, X. Y.; Friend, C. M. Partial oxidation of propene on oxygen-covered Au (111). J. Phys. Chem. B 2006, 110, 15982–15987.

[36]

Van Hardeveld, R.; Hartog, F. The statistics of surface atoms and surface sites on metal crystals. Surf. Sci. 1969, 15, 189–230.

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Publication history
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Acknowledgements

Publication history

Received: 25 August 2022
Revised: 20 October 2022
Accepted: 31 October 2022
Published: 27 December 2022
Issue date: May 2023

Copyright

© Tsinghua University Press 2022

Acknowledgements

Acknowledgements

This work was financially supported by the National Key R&D Program of China (No. 2021YFA1501403), the National Natural Science Foundation of China (Nos. 21922803, 22038003, 92034301, 22008066, and 21776077), the Innovation Program of Shanghai Municipal Education Commission, the Program of Shanghai Academic/Technology Research Leader (No. 21XD1421000), the Shanghai Science and Technology Innovation Action Plan (No. 22JC1403800), the China Postdoctoral Science Foundation (No. BX20190116), and 111 Project of the Ministry of Education of China (No. B08021).

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