Manipulation of hydroisomerization performance on Pt/ZSM-23 by introducing Al2O3

被引：5
作者：
Bai D. [1 ]
Meng J.-P. [1 ]
Zou C. [1 ]
Li C. [1 ]
Liang C.-H. [1 ]
机构：
[1] Laboratory of Advanced Materials and Catalytic Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian
来源：
Ranliao Huaxue Xuebao/Journal of Fuel Chemistry and Technology | 2023年 / 51卷 / 02期
基金：
中国国家自然科学基金;
关键词：
Al[!sub]2[!/sub]O[!sub]3[!/sub; hydroisomerization; n-hexadecane; ZSM-23;
D O I：
10.1016/S1872-5813(22)60034-3
中图分类号：
学科分类号：
摘要：
ZSM-23 zeolite was successfully synthesized in a dual-template system, and ZSM-23-Al2O3 composites with different ratios were also prepared. The hydroisomerization performance of Pt/ZSM-23 catalyst was manipulated by introducing Al2O3, and the influence of Al2O3 on physicochemical properties was investigated by XRD, SEM, TEM, N2 physical adsorption-desorption and NH3-TPD characterizations. The results showed that Al2O3 improved the dispersion of Pt, significantly reduced the acid sites concentration of the catalyst, and regulated the metal-acid balance in quantitative. The suitable metal-acid balance concentration could improve the selectivity of isomers and suppress the cracking reactions. Meanwhile, Al2O3 dispersed the ZSM-23 grains, which improved the dispersion and increased the number of exposed pores in ZSM-23. Thus the diffusion efficiency of reactants and intermediates could be promoted and the isomer products selectivity could be improved. All composite catalysts showed high selectivity of isomer products, among which, Pt/(9Z-1Al) had the highest yield of isomer products due to its suitable metal-acid concentration balance, reached 60% at 340 ℃, which was a significant improvement compared with Pt/ZSM-23 (42%). When the reaction temperature was lower than 310 ℃, the pore mouth mechanism dominated in Pt/ZSM-23, while the key-lock mechanism was significantly strengthened at higher reaction temperature. After the introduction of Al2O3, more adjacent pores in ZSM-23 were exposed and the key-lock mechanism became the domination, which led to a large number of 7/8Me-C15 isomers. © 2023 Science Press. All rights reserved.
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页码：175 / 185
页数：10
相关论文
共 34 条
[1]  
ZHANG S, ZHANG Y, TIERNEY J W, WENDER I., Anion-modified zirconia: Effect of metal promotion and hydrogen reduction on hydroisomerization of n-hexadecane and Fischer-Tropsch waxes[J], Fuel Process Technol, 69, 1, (2001)
[2]  
CALEMMA V, PERATELLO S, PEREGO C., Hydroisomerization and hydrocracking of long chain n-alkanes on Pt/amorphous SiO2-Al2O3 catalyst[J], Appl Catal A: Gen, 190, 1/2, pp. 207-218, (2000)
[3]  
REGALI F, LIOTTA L F, VENEZIA A M, MONTES V, BOUTONNET M, JRS S., Effect of metal loading on activity, selectivity and deactivation behavior of Pd/silica-alumina catalysts in the hydroconversion of n-hexadecane[J], Catal Today, 223, 3, (2014)
[4]  
MARTENS J A, VANBUTSELE, JACOBS P A, DENAYER OCAKOGLU, Evidences for pore mouth and key-lock catalysis in hydroisomerization of long n-alkanes over 10-ring tubular pore bifunctional zeolites[J], Catal Today, 65, 2, (2001)
[5]  
MARTENS J A, JACOBS P A, WEITKAMP J., Attempts to rationalize the distribution of hydrocracked products. I qualitative description of the primary hydrocracking modes of long chain paraffins in open zeolites[J], Appl Catal, 20, 1/2, pp. 239-281, (1986)
[6]  
ZHANG M, LIU Q, LONG H, SUN L, MURAYAMA T, QI C., Insights into Au nanoparticle size and chemical state of Au/ZSM-5 catalyst for catalytic cracking of n-octane to increase propylene production[J], J Phys Chem C, 125, 29, pp. 16013-16023, (2021)
[7]  
HOU Ran-ran, HU Zhi-hai, GUO Qing-zhou, BI Yun-fei, GAO Jie, LI Hong-hui, Effects of catalysts on catalytic performance in long chain n-alkanes isomerization[J], Acta Pet Sin(Pet Process Sect), 38, 1, pp. 20-28, (2022)
[8]  
BURTON A W., A priori phase prediction of zeolites: Case study of the structure-directing effects in the synthesis of MTT-type zeolites[J], J Am Chem Soc, 129, 24, (2007)
[9]  
JR A, LAPIERRE R B, SCHLENKER J L, WOOD J D, VALYOCSIK E W, RUBIN M K, HIGGINS J B, ROHRBAUGH W J., The framework topology of ZSM-23: A high silica zeolite[J], Zeolites, 5, 6, (1985)
[10]  
HOLZINGER J, NIELSEN M, BEATO P, BROGAARD R Y, BUONO C, DYBALLA M., Identification of distinct framework aluminum sites in zeolite ZSM-23: A combined computational and experimental 27Al NMR study[J], J Phys Chem C, 123, 13, pp. 7831-7844, (2019)
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