The carboxylates formed on oxides promoting the aromatization in syngas conversion over composite catalysts

doi:10.1016/S1872-2067(20)63691-9

Abstract

Abstract:

Syngas to aromatics (STA) over bifunctional catalysts has attracted much attention in recent years, but the mechanism underlying the formation of aromatics remains controversial. The critical reaction intermediates, carboxylates, were first identified and then confirmed to essentially promote aromatization in the syngas conversion over a ZnCrAlO_x&H-ZSM-5 composite catalyst. This study provides evidence that the carboxylates can be formed during the reactions of formate species and olefins. In addition, it is shown that the carboxylates favor the formation of aromatics over H-ZSM-5 even in the presence of H₂. A novel mechanism for the formation of aromatics via the generation and transformation of carboxylate intermediates is proposed, and the transformation of carboxylates to aromatics via methyl-2-cyclopenten-1-one (MCPO) intermediates is indeed likely. A better understanding of the formation mechanism of aromatics would help optimize the composite catalyst.

Key words: Carboxylates, Syngas-to-aromatics, Composite catalysts, ZnCrAlO_x, H-ZSM-5

Zhiyang Chen, Youming Ni, Fuli Wen, Ziqiao Zhou, Wenliang Zhu, Zhongmin Liu. The carboxylates formed on oxides promoting the aromatization in syngas conversion over composite catalysts[J]. Chinese Journal of Catalysis, 2021, 42(5): 835-843.

×
share this article

Add to citation manager EndNote|Ris|BibTeX

URL: https://www.cjcatal.com/EN/10.1016/S1872-2067(20)63691-9

https://www.cjcatal.com/EN/Y2021/V42/I5/835

Figures/Tables 12

Fig. 1. Comparison of catalytic results for syngas and methanol conversion. (a) Syngas conversion over various composite catalysts. Space velocity = 2000 (only for ZnCrAlOx) or 1500 (for other catalysts) mL g-1 h-1, 4.0 MPa, H2/CO/Ar = 47.5:47.5:5, 633 K , time on stream = 3 h. Note that C5+ excludes aromatics; ZnCrAlOx&H-ZSM-5 prepared by grinding; ZnCrAlOx+H-ZSM-5 prepared by mixing granules; ZnCrAlOx/H-ZSM-5 denoted as dual-bed catalysts. (b) Methanol conversion over H-ZSM-5 and ZnCrAlOx&H-ZSM-5 in various atmospheres. Space velocity = 6000 (for H-ZSM-5) and 1500 (for ZnCrAlOx&H-ZSM-5) mL g-1 h-1, liquid MeOH flow rate: 0.004 mL min-1, 633 K, 4.0 Mpa, time on stream = 3 h. N2+H2 denotes N2/H2/MeOH = 4:4:1, N2 denotes N2/MeOH = 8:1, CO+H2 denotes CO/H2/MeOH = 4:4:1, N2+CO denotes N2/CO/MeOH = 4:4:1.

Fig. 2. Relationship between lower olefins and aromatics during the reactions. (a) Effect of space velocity on the formation of lower olefins and aromatics in syngas conversion over ZnCrAlOx&H-ZSM-5. 4.0 MPa, H2/CO/Ar = 47.5:47.5:5, 633 K, time on stream = 4 h. (b) Conversion of propene over various catalysts in CO. Reaction conditions: 633 K, 4 MPa, CO:He:C3H6 = 20:19:1, space velocity = 6000 (for H-ZSM-5) and 1500 (for other catalysts) mL h-1 g-1, time on stream = 4 h.

Fig. 3. In situ DRIFT spectra for the conversion of CO and C3H6 over ZnCrAlOx (a) and ZnCrAlOx&H-ZSM-5 (b). Reaction conditions: 0.1 MPa, 573 K, CO = 5 mL min-1, C3H6 (5%C3H6+95% N2) = 5 mL min-1.

Fig. 4. Identification of carboxylates. (a) GC-MS profiles of products for the conversion of the mixture of CO, H2, ethanol and C3H6 over ZnCrAlOx. Catalyst mass = 0.3 g, space velocity = 2000 mL min-1, CO/H2/EtOH/C3H6 (molar ratio) = 42.5:42.5:13.0:7.0, 0.1 MPa, 573 K. (b) DRIFT spectra of zinc methacrylate as stand reference.

Fig. 5. Investigation of the role of carboxylates in the formation of aromatics via the STA reaction. (a) Effect of co-feeding methyl crotonate with C3H6 over H-ZSM-5 in N2 atmosphere. 633 K, 0.1 Mpa, space velocity = 1500 ml h-1 gcat-1, time on stream = 2 h. (b) Comparisons of propene and carboxylates conversions over H-ZSM-5 in N2 or H2. 1.0 MPa, 633 K, ratio of N2 or H2/C3H6 to methyl crotonate or methyl butyrate = 81 (on a carbon basis), time on stream = 2 h.

Fig. 6. The effect of the proximity of oxide and zeolite on the acidic property of H-ZSM-5 and the formation of retained organics. (a) FTIR subtraction relative to adsorption of DTBPy. (b) GC-MS chromatograms of retained organics in various catalysts after syngas conversion. Space velocity = 1500 mL g-1 h-1, 4.0 MPa, H2/CO/Ar = 47.5/47.5/5, 633 K, time on stream = 1 min. Peak numbers correspond to compounds listed in Table S1.

Scheme 1. Proposed mechanism of the STA reaction over a composite catalyst. M denotes ZnCrAlOx; R, R1, and R2 denote H and alkyl groups.

References

[1]	A. M. Niziolek, O. Onel, C. A. Floudas, ALChE J., 2016,62, 1531-1556.
[2]	N. Duyckaerts, M. Bartsch, I. T. Trotus, N. Pfander, A. Lorke, F. Schuth, G. Prieto, Angew. Chem. Int. Ed., 2017,56, 11480-11484.
[3]	N. Li, F. Jiao, X. Pan, Y. Chen, J. Feng, G. Li, X. Bao, Angew. Chem. Int. Ed., 2019,58, 7400-7404.
[4]	F. Jiao, J. Li, X. Pan, J. Xiao, H. Li, H. Ma, M. Wei, Y. Pan, Z. Zhou, M. Li, S. Miao, J. Li, Y. Zhu, D. Xiao, T. He, J. Yang, F. Qi, Q. Fu, X. Bao, Science, 2016,351, 1065-1068.
[5]	K. Cheng, B. Gu, X. Liu, J. Kang, Q. Zhang, Y. Wang, Angew. Chem. Int. Ed., 2016,55, 4725-4728.
[6]	C. D. Chang, W. H. Lang, A. J. Silvestri, J. Catal., 1979,56, 268-273.
[7]	S. Sartipi, M. Makkee, F. Kapteijn, J. Gascon, Catal. Sci. Technol., 2014,4, 893-907.
[8]	B. Zhao, P. Zhai, P. Wang, J. Li, T. Li, M. Peng, M. Zhao, G. Hu, Y. Yang, Y.-W. Li, Q. Zhang, W. Fan, D. Ma, Chem, 2017,3, 323-333.
[9]	Y. Xu, D. Liu, X. Liu, Appl. Catal. A, 2018,552, 168-183.
[10]	Y. Xu, J. Liu, J. Wang, G. Ma, J. Lin, Y. Yang, Y. Li, C. Zhang, M. Ding, ACS Catal., 2019,9, 5147-5156.
[11]	K. Cheng, W. Zhou, J. Kang, S. He, S. Shi, Q. Zhang, Y. Pan, W. Wen, Y. Wang, Chem, 2017,3, 334-347.
[12]	J. Yang, X. Pan, F. Jiao, J. Li, X. Bao, Chem. Commun., 2017,53, 11146-11149.
[13]	Z. Huang, S. Wang, F. Qin, L. Huang, Y. Yue, W. Hua, M. Qiao, H. He, W. Shen, H. Xu, ChemCatChem, 2018,10, 4519-4524.
[14]	W. Zhou, S. Shi, Y. Wang, L. Zhang, Y. Wang, G. Zhang, X. Min, K. Cheng, Q. Zhang, J. Kang, Y. Wang, ChemCatChem, 2019,11, 1681-1688.
[15]	Y. Fu, Y. Ni, W. Zhu, Z. Liu, J. Catal., 2020,383, 97-102.
[16]	M. T. Arslan, B. A. Qureshi, S. Z. A Gilani, D. Cai, Y. Ma, M. Usman, X. Chen, Y. Wang, F. Wei, ACS Catal., 2019,9, 2203-2212.
[17]	M. T. Arslan, B. Ali, S. Z. A Gilani, Y. Hou, Q. Wang, D. Cai, Y. Wang, F. Wei, ACS Catal., 2020,10, 2477-2488.
[18]	Z. Chen, Y. Ni, Y. Zhi, F. Wen, Z. Zhou, Y. Wei, W. Zhu, Z. Liu, Angew. Chem. Int. Ed., 2018,57, 12549-12553.
[19]	M. Guisnet, P. Magnoux, Appl. Catal., 1989,54, 1-27.
[20]	J. Kanai, J. A. Martens, P. A. Jacobs, J. Catal., 1992,133, 527-543.
[21]	R. Gounder, E. Iglesia, J. Catal., 2011,277, 36-45.
[22]	S. S. Arora, D. L. S Nieskens, A. Malek, A. Bhan, Nat. Catal., 2018,1, 666-672.
[23]	X. Zhao, J. Li, P. Tian, L. Wang, X. Li, S. Lin, X. Guo, Z. Liu, ACS Catal., 2019,9, 3017-3025.
[24]	Y. Song, X. Zhu, S. Xie, Q. Wang, L. Xu, Catal. Lett., 2004,97, 31-36.
[25]	Y. Ni, A. Sun, X. Wu, J. Hu, T. Li, G. Li, Chin. J. Chem. Eng., 2011,19, 439-445.
[26]	V. R. Choudhary, V. S. Nayak, Zeolites, 1985,5, 325-328.
[27]	Z. Li, Y. Qu, J. Wang, H. Liu, M. Li, S. Miao, C. Li, Joule, 2019,3, 570-583.
[28]	X. Sun, S. Mueller, H. Shi, G. L. Haller, M. Sanchez-Sanchez, A. C. van Veen, J. A. Lercher, J. Catal., 2014,314, 21-31.
[29]	S. Ilias, A. Bhan, ACS Catal., 2012,3, 18-31.
[30]	X. Sun, S. Mueller, Y. Liu, H. Shi, G. L. Haller, M. Sanchez-Sanchez, A. C. van Veen, J. A. Lercher, J. Catal., 2014,317, 185-197.
[31]	S. Fujita, M. Usui, H. Ito, N. Takezawa, J. Catal., 1995,157, 403-413.
[32]	X. Liu, W. Zhou, Y. Yang, K. Cheng, J. Kang, L. Zhang, G. Zhang, X. Min, Q. Zhang, Y. Wang, Chem. Sci., 2018,9, 4708-4718.
[33]	N. B. Jackson, J. G. Ekerdt, J. Catal., 1986,101, 90-102.
[34]	L. Palumbo, F. Bonino, P. Beato, M. Bjørgen, A. Zecchina, S. Bordiga, J. Phys. Chem. C, 2008,112, 9710-9716.
[35]	M. Rozwadowski, M. Lezanska, J. Wloch, K. Erdmann, R. Golembiewski, J. Kornatowski, Chem. Mater., 2001,13, 1609-1616.
[36]	Y. Yang, L. Wang, K. Xiao, T. Zhao, H. Wang, L. Zhong, Y. Sun, Catal. Sci. Technol., 2015,5, 4224-4232.
[37]	Y. Liu, F. M. Kirchberger, S. Muller, M. Eder, M. Tonigold, M. Sanchez-Sanchez, J. A. Lercher, Nat. Commun., 2019,10, 1462.
[38]	T. Lin, X. Qi, X. Wang, L. Xia, C. Wang, F. Yu, H. Wang, S. Li, L. Zhong, Y. Sun, Angew. Chem. Int. Ed., 2019,58, 4627-4631.
[39]	H. T. Luk, C. Mondelli, D. C. Ferre, J. A. Stewart, J. Perez-Ramirez, Chem. Soc. Rev., 2017,46, 1358-1426.
[40]	Y. Ni, Z. Chen, Y. Fu, Y. Liu, W. Zhu, Z. Liu, Nat. Commun., 2018,9, 3457.
[41]	A. Ungureanu, T. V. Hoang, D. Trong On, E. Dumitriu, S. Kaliaguine, Appl. Catal. A, 2005,294, 92-105.
[42]	Z. Liu, X. Dong, X. Liu, Y. Han, Catal. Sci. Technol., 2016,6, 8157-8165.
[43]	L. Yang, T. Yan, C. Wang, W. Dai, G. Wu, M. Hunger, W. Fan, Z. Xie, N. Guan, L. Li, ACS Catal., 2019,9, 6491-6501.
[44]	Y. Ni, W. Zhu, Z. Liu, ACS Catal., 2019,9, 11398-11403.