Synthesis of lamellar PtZn@Silicalite-1 zeolite and its catalytic properties for propane dehydrogenation

doi:10.11949/0438-1157.20240318

Abstract

Abstract:

The lamellar Silicalite-1 zeolite (PtZn@Silicalite-1) encapsulated PtZn nano-alloy was synthesized in one step by hydrothermal crystallization method with tetramethylguanidine (TMG) as morphology regulator. The catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), and their catalytic performance for propane dehydrogenation was investigated. The results show that the addition of TMG can effectively regulate the growth orientation of Silicalite-1 zeolite crystals, and the crystal size along the b-axis is inversely proportional to the ratio of TMG/SiO₂. At 550℃ and in pure propane atmosphere, the lamellar PtZn@Silicalite-1 catalyst showed excellent propane dehydrogenation performance. After 20 h of continuous reaction, its deactivation constant was only 0.007 h^-1, while that of the conventional PtZn@Silicalite-1 catalyst was 0.013 h^-1. Combined with the characterization data, the lamellar zeolite catalyst has larger external specific surface area and shorter b-axis through channel, which improves the accessibility of the dehydrogenation active site and shortens the diffusion path of gas molecules in the pore, thus improving the activity and stability of the catalyst.

Key words: lamellar shape, Silicalite-1 zeolite, PtZn alloy, encapsulation, propane dehydrogenation

摘要：

采用水热晶化法，以四甲基胍（TMG）为形貌调控剂，一步合成封装PtZn纳米合金的薄片状Silicalite-1分子筛（PtZn@Silicalite-1）。采用X射线衍射（XRD）、透射电子显微镜（TEM）、X射线光电子能谱（XPS）等技术对样品进行表征分析，并考察了其丙烷脱氢催化性能。结果显示，加入TMG可有效调控Silicalite-1分子筛晶体的生长取向，晶体沿b轴的尺寸与TMG/SiO₂的比值呈反比。在550℃和纯丙烷气氛下，片状PtZn@Silicalite-1催化剂表现出优异的丙烷脱氢性能，经过20 h的连续反应，其失活常数仅为0.007 h^-1，而常规PtZn@Silicalite-1催化剂为0.013 h^-1。结合表征结果，薄片状分子筛催化剂具有更大的外比表面积和更短的b轴直通道，这提高了脱氢活性位的可接近性，缩短了气体分子在孔道中的扩散路径，从而提升了催化剂的活性和稳定性。

关键词: 薄片形貌, Silicalite-1分子筛, PtZn合金, 封装, 丙烷脱氢

CLC Number:

TQ 032.4

Jingyu WANG, Jia LIU, Jixiang XU, Lei WANG. Synthesis of lamellar PtZn@Silicalite-1 zeolite and its catalytic properties for propane dehydrogenation[J]. CIESC Journal, 2024, 75(9): 3188-3197.

王靖宇, 刘佳, 徐继香, 王磊. 薄片状PtZn@Silicalite-1分子筛的合成及催化丙烷脱氢性能研究[J]. 化工学报, 2024, 75(9): 3188-3197.

Figures/Tables 12

Fig.1 SEM images of PtZn@Silicalite-1 zeolite with different TMG/SiO2 molar ratios

Fig.2 The relationship between different TMG/SiO2 molarratios and average b-axis thickness of zeolite crystals

Fig.3 Pt contents, Zn contents and Zn/Pt ratios of PtZn@Silicalite-1 catalysts synthesized with different TMG contents

Fig.4 XRD patterns of PtZn@S-1-0TMG and PtZn@S-1-0.5TMG catalysts

Fig.5 Transmission electron microscopy characterization of PtZn@S-1-0TMG [(a)—(e)] and PtZn@S-1-0.5TMG [(f)—(j)] catalysts

Fig.6 Pt 4f XPS spectra of PtZn@S-1-0TMG and PtZn@S-1-0.5TMG catalysts

Fig.7 N2 adsorption-desorption characterization of PtZn@S-1-0TMG and PtZn@S-1-0.5TMG catalysts

Table 1 Physicochemical properties of as-prepared PtZn@Silicalite-1 catalysts

样品

S_micro/

(m²/g)

S_external/

(m²/g)

V_micro/

(cm³/g)

Fig.8 Propane diffusion kinetics results of PtZn@S-1-0TMG and PtZn@S-1-0.5TMG catalysts at different temperatures

Fig.9 Propane dehydrogenation performance of PtZn@S-1-0TMG and PtZn@S-1-0.5TMG catalysts （reaction conditions: 550℃, 101325 Pa, pure propane, WHSV=15.1 h-1）

Fig.10 TG analysis curves of spent PtZn@S-1-0TMG and PtZn@S-1-0.5TMG catalysts

Fig.11 Activation energy characterization of PtZn@S-1-0TMG and PtZn@S-1-0.5TMG catalysts

References 31

1	James O O, Mandal S, Alele N, et al. Lower alkanes dehydrogenation: strategies and reaction routes to corresponding alkenes[J]. Fuel Processing Technology, 2016, 149: 239-255.
2	Atanga M A, Rezaei F, Jawad A, et al. Oxidative dehydrogenation of propane to propylene with carbon dioxide[J]. Applied Catalysis B: Environmental, 2018, 220: 429-445.
3	Sattler J J H B, Ruiz-Martinez J, Santillan-Jimenez E, et al. Catalytic dehydrogenation of light alkanes on metals and metal oxides[J]. Chemical Reviews, 2014, 114(20): 10613-10653.
4	Zhao Z J, Chiu C C, Gong J L. Molecular understandings on the activation of light hydrocarbons over heterogeneous catalysts[J]. Chemical Science, 2015, 6(8): 4403-4425.
5	Chen S, Chang X, Sun G D, et al. Propane dehydrogenation: catalyst development, new chemistry, and emerging technologies[J]. Chemical Society Reviews, 2021, 50(5): 3315-3354.
6	Hu Z P, Yang D D, Wang Z, et al. State-of-the-art catalysts for direct dehydrogenation of propane to propylene[J]. Chinese Journal of Catalysis, 2019, 40(9): 1233-1254.
7	Nawaz Z. Light alkane dehydrogenation to light olefin technologies: a comprehensive review[J]. Reviews in Chemical Engineering, 2015, 31(5): 413-436.
8	Carter J H, Bere T, Pitchers J R, et al. Direct and oxidative dehydrogenation of propane: from catalyst design to industrial application[J]. Green Chemistry, 2021, 23(24): 9747-9799.
9	Wang G W, Zhang S, Zhu X L, et al. Dehydrogenation versus hydrogenolysis in the reaction of light alkanes over Ni-based catalysts[J]. Journal of Industrial and Engineering Chemistry, 2020, 86: 1-12.
10	Wu J, Mallikarjun Sharada S, Ho C, et al. Ethane and propane dehydrogenation over PtIr/Mg(Al)O[J]. Applied Catalysis A: General, 2015, 506: 25-32.
11	Kaylor N, Davis R J. Propane dehydrogenation over supported Pt-Sn nanoparticles[J]. Journal of Catalysis, 2018, 367: 181-193.
12	Nakaya Y, Hirayama J, Yamazoe S, et al. Single-atom Pt in intermetallics as an ultrastable and selective catalyst for propane dehydrogenation[J]. Nature Communications, 2020, 11(1): 2838.
13	Gao X F, Xu W H, Li X, et al. Non-oxidative dehydrogenation of propane to propene over Pt-Sn/Al₂O₃ catalysts: identification of the nature of active site[J]. Chemical Engineering Journal, 2022, 443: 136393.
14	Sun Q M, Wang N, Fan Q Y, et al. Subnanometer bimetallic platinum-zinc clusters in zeolites for propane dehydrogenation[J]. Angewandte Chemie International Edition, 2020, 59(44): 19450-19459.
15	Rochlitz L, Searles K, Alfke J, et al. Silica-supported, narrowly distributed, subnanometric Pt-Zn particles from single sites with high propane dehydrogenation performance[J]. Chemical Science, 2020, 11(6): 1549-1555.
16	Qiu Y, Li X Y, Zhang Y Y, et al. Various metals (Ce, In, La, and Fe) promoted Pt/Sn-SBA-15 as highly stable catalysts for propane dehydrogenation[J]. Industrial & Engineering Chemistry Research, 2019, 58(25): 10804-10818.
17	Wang G J, Lu K, Yin C Q, et al. One-step fabrication of PtSn/γ-Al₂O₃ catalysts with La post-modification for propane dehydrogenation[J]. Catalysts, 2020, 10(9): 1042.
18	Searles K, Chan K W, Mendes Burak J A, et al. Highly productive propane dehydrogenation catalyst using silica-supported Ga-Pt nanoparticles generated from single-sites[J]. Journal of the American Chemical Society, 2018, 140(37): 11674-11679.
19	Zhang J X, Ren L M, Zhou A J, et al. Tailored synthesis of ZSM-5 nanosheets with controllable b-axis thickness and aspect ratio: strategy and growth mechanism[J]. Chemistry of Materials, 2022, 34(7): 3217-3226.
20	Shang Z Y, Chen Y, Zhang L J, et al. Constructing single-crystalline hierarchical plate-like ZSM-5 zeolites with short b-axis length for catalyzing MTO reactions[J]. Inorganic Chemistry Frontiers, 2022, 9(7): 1456-1466.
21	王子健, 柯明, 李佳涵, 等. 短b轴ZSM-5分子筛制备方法及应用研究进展[J]. 化工学报, 2023, 74(4): 1457-1473.
	Wang Z J, Ke M, Li J H, et al. Progress in preparation and application of short b-axis ZSM-5 molecular sieve[J]. CIESC Journal, 2023, 74(4): 1457-1473.
22	Zhang B F, Li G Z, Liu S B, et al. Boosting propane dehydrogenation over PtZn encapsulated in an epitaxial high-crystallized zeolite with a low surface barrier[J]. ACS Catalysis, 2022, 12(2): 1310-1314.
23	Dai W J, Kouvatas C, Tai W S, et al. Platelike MFI crystals with controlled crystal faces aspect ratio[J]. Journal of the American Chemical Society, 2021, 143(4): 1993-2004.
24	Li Z Z, Liao Y Q, Wang Y D, et al. A co-solvent in aqueous electrolyte towards ultralong-life rechargeable zinc-ion batteries[J]. Energy Storage Materials, 2023, 56: 174-182.
25	Han A J, Zhang J, Sun W M, et al. Isolating contiguous Pt atoms and forming Pt-Zn intermetallic nanoparticles to regulate selectivity in 4-nitrophenylacetylene hydrogenation[J]. Nature Communications, 2019, 10(1): 3787.
26	Kuroki H, Matsumoto M, Tamaki T, et al. Analysis of oxidized Pt species on a connected Pt-Fe catalyst with enhanced oxygen reduction activity probed by electrochemical XPS[J]. Journal of Chemical Engineering of Japan, 2023, 56(1): 2197946.
27	Zhang L K, Ma Y, Liu C C, et al. Demetallation and reduction induced ultra-dispersed PtZn alloy confined in zeolite for propane dehydrogenation[J]. Chinese Journal of Catalysis, 2023, 55: 241-252.
28	Zhang Y N, Zhang X Y, Yang P F, et al. In situ topologically induced PtZn alloy @ ZnTiO _x and the synergistic effect on glycerol oxidation[J]. Applied Catalysis B: Environmental, 2021, 298: 120634.
29	Nykänen L, Honkala K. Density functional theory study on propane and propene adsorption on Pt(111) and PtSn alloy surfaces[J]. The Journal of Physical Chemistry C, 2011, 115(19): 9578-9586.
30	Shan Y L, Sui Z J, Zhu Y A, et al. Effect of steam addition on the structure and activity of Pt-Sn catalysts in propane dehydrogenation[J]. Chemical Engineering Journal, 2015, 278: 240-248.
31	Li Q, Sui Z J, Zhou X G, et al. Kinetics of propane dehydrogenation over Pt-Sn/Al₂O₃ catalyst[J]. Applied Catalysis A: General, 2011, 398(1/2): 18-26.

[1]	Chan WANG, Guoxi XIAO, Xiaoxue GUO, Renwei XU, Yuanyuan YUE, Xiaojun BAO. Green synthesis and application of Beta zeolite prepared via mesoscale depolymerization-reorganization strategy [J]. CIESC Journal, 2022, 73(6): 2690-2697.
[2]	Feng YE, Gang LI, Xin FU, Xuemei LANG, Yanhong WANG, Shenglong WANG, Jianli ZHANG, Shuanshi FAN. A simulation study on propane dehydrogenation in porous membrane reactors for propylene production [J]. CIESC Journal, 2022, 73(5): 2008-2019.
[3]	Wenying LIU, Xiaojie JU, Rui XIE, Wei WANG, Zhuang LIU, Liangyin CHU. Recent progress in preparation of functional capsule membranes based on co-extrusion minifluidic technique [J]. CIESC Journal, 2020, 71(10): 4365-4378.
[4]	SU Yunxiang, QUAN Xuebo, MIN Wenfeng, QIAO Laicong, LI Libo, ZHOU Jian. Dissipative particle dynamics simulations on loading and release of doxorubicin by PAMAM dendrimers [J]. CIESC Journal, 2017, 68(5): 1757-1766.
[5]	CHEN Sufen, LIU Yiyang, SU Lin, QI Xiaobo, SHI Ruiting, LIU Meifang, ZHANG Zhanwen, LI Bo. Influence of double emulsions solidification rate on sphericity of poly(α-methyl styrene)capsules in microencapsulation process [J]. CIESC Journal, 2013, 64(7): 2446-2452.
[6]	LI Qing, SUI Zhijun, ZHU Yi, ZHOU Xinggui, CHEN De. Formation of coke on Pt catalysts during propane dehydrogenation: effect of Pt particle size and Sn addition [J]. CIESC Journal, 2013, 64(2): 524-531.
[7]	XIA Fei, JIN Heyang, ZHAO Yaping, GUO Xinqiu. Supercritical Antisolvent-based Technology for Preparation of Vitamin D₃ Proliposome and Its Characteristics [J]. , 2011, 19(6): 1039-1046.
[8]	ZHANG Zhengguo，YAN Zhipeng，FANG Xiaoming，FANG Yutang，GAO Xuenong. Research development of applications of nanotechnology in heat transfer enhancement [J]. , 2011, 30(1): 34-.
[9]	LIU Jiefeng, REN Yiran, YAO Shanjing. Repeated-batch Cultivation of Encapsulated Monascus purpureus by Polyelectrolyte Complex for Natural Pigment Production [J]. , 2010, 18(6): 1013-1017.
[10]	ZHANG Xinping, SUI Zhijun, ZHOU Xinggui, YUAN Weikang. Modeling and Simulation of Coke Combustion Regeneration for Coked Cr₂O₃/Al₂O₃ Propane Dehydrogenation Catalyst [J]. , 2010, 18(4): 618-625.
[11]	GAO Aihuan，PI Pihui，WEN Xiufang，CHENG Jiang，YANG Zhuoru. Research progress of surface modification of aluminum pigments for corrosion protection [J]. , 2009, 28(3): 485-.
[12]	LIU Zhengping, PEI Lixia, JI Hongbing, YAO Xingdong. Preparation of Well-shaped Microcapsule Immobilizing Inorganic Nanoparticles [J]. , 2008, 16(3): 384-388.
[13]	ZHANG Faxing，LIU Yaqing，WEI Xiaoli，XU Zheng. Research on red phosphorus microencapsulation flame retardant prepared by SCF-RESS [J]. , 2007, 26(5): 690-.
[14]	YUAN Xia，FANG Kuanjun. Procedures of hydrophilic modification of carbon black surface [J]. , 2007, 26(5): 657-.
[15]	JING Legang，ZHAO Xinhuai. Preparation and applications of microencapsulation of vitamin C [J]. , 2006, 25(11): 1256-.