柠檬酸复合改性对多环芳烃选择性开环铂/Beta催化剂性能的影响

doi:10.19964/j.issn.1006-4990.2020-0647

摘要/Abstract

摘要：

通过水热处理、柠檬酸处理及其复合处理对Beta分子筛进行后改性,并以改性后的载体制得铂/Beta催化剂。采用X射线衍射（XRD）、X射线荧光光谱仪（XRF）、程序升温脱附（NH₃-TPD）、红外吡啶吸附（Py-IR）、骨架铝核磁共振技术（²⁷Al MAS NMR）及骨架硅核磁共振技术（²⁹Si MAS NMR）等表征了改性前后Beta分子筛的物化性质,并考察了改性前后铂/Beta的多环芳烃选择性开环性能。结果表明,Beta分子筛在柠檬酸处理过程中可同时发生络合脱铝与骨架补铝,实现骨架铝的再分布;Beta分子筛在水热处理过程中优先脱除稳定性相对较低的Si（2 Al）处骨架铝,产生骨架缺陷的同时生成一定比例的二次介孔结构;水热-柠檬酸复合处理影响Beta分子筛骨架补铝及骨架铝再分布的效果,水热处理后Beta分子筛中存在更多的骨架缺陷,促进活性Al（OH）₂⁺物种的骨架补铝作用。当Beta分子筛采用水热-柠檬酸复合处理顺序时,骨架补铝及骨架铝再分布效果显著,样品以中强酸为主,且具有较高的B酸量与L酸量的比值,所制备催化剂的多环芳烃选择性开环活性及稳定性最优。

关键词: Beta分子筛, 柠檬酸处理, 水热处理, 多环芳烃, 选择性开环

Abstract:

Beta zeolites were post modified by hydrothermal treatment,citric acid treatment and duplex treatment,and the Pt/beta catalyst was prepared with the modified support.The physicochemical properties of the the modified and unmodified beta zeolites were characterized by X-ray diffraction（XRD）,X-ray fluorescence spectrometry（XRF）,temperature programmed desorption（NH₃-TPD）,infrared pyridine adsorption（Py-IR）,framework aluminum nuclear magnetic resonance（²⁷Al MAS NMR） and framework silicon nuclear magnetic resonance（²⁹Si MAS NMR）,and the performance of the modified and unmod-ified Pt/beta on selective ring opening of polycyclic aromatic were investigated.The results showed that dealumination and re-alumination of Beta zeolite performed in citric acid treatment,leading to framework Al redistribution.In the process of hydro-thermal treatment,beta zeolite preferentially removed the framework aluminum at Si（2Al）,which had relatively low stability,and produced framework defects and a certain proportion of secondary mesoporous structure.The hydrothermal-citric acid du-plex treatment made a difference to framework aluminum addition and redistribution of beta zeolite.After hydrothermal treat-ment,there were more framework defects in beta molecular sieves,which could promote the framework supplement of active Al（OH）₂⁺ species.When the hydrothermal-citric acid duplex treatment sequence was used for beta zeolite,the effect of frame-work aluminum supplement and framework aluminum redistribution was significant.The sample was mainly medium strong acid with a high ratio of B acid content to L acid content.The as-prepared catalyst had the best selective ring opening activity and stability for polycyclic aromatic hydrocarbons.

Key words: beta zeolite, citric acid treatment, hydrothermal treatment, polycyclic aromatic hydrocarbons, selective ring opening

中图分类号:

O643.36

臧甲忠,马明超,于海斌,范景新,郭春垒,靳凤英. 柠檬酸复合改性对多环芳烃选择性开环铂/Beta催化剂性能的影响[J]. 无机盐工业, 2021, 53(6): 205-211.

Zang Jiazhong,Ma Mingchao,Yu Haibin,Fan Jingxin,Guo Chunlei,Jin Fengying. Effect of citric acid assisted hydrothermal dealumination on performance of Pt/Beta catalysts for selective ring opening of polycyclic aromatic hydrocarbons[J]. Inorganic Chemicals Industry, 2021, 53(6): 205-211.

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参考文献 24

[1]	谢朝钢, 叶岗. 市场导向炼油企业转型升级的技术选择[J]. 石油炼制与化工, 2019,50(4):1-6.
[2]	辛靖, 高杨, 侯章贵, 等. 以生产轻芳烃为目的的催化重整装置原料拓展研究进展[J]. 无机盐工业, 2019,51(7):1-7.
[3]	Lee J, Choi Y, Shin J, et al. Selective hydrocracking of tetralin for light aromatic hydrocarbons[J]. Catalysis Today, 2016,265:144-153. doi: 10.1016/j.cattod.2015.09.046
[4]	Kenmogne R, Finiels A, Cammarano C, et al. Hydroconversion of nhexadecane over bifunctional microporous and mesoporous model catalysts influence of pore architecture on selectivity[J]. Journal of Catalysis, 2015,329:348-354. doi: 10.1016/j.jcat.2015.05.026
[5]	Kubicka D, Kumar N, Mäki-Arvela P, et al. Ring opening of decalin over zeolites:Ⅱ.activity and selectivity of platinum-modified zeolit-es[J]. Journal of Catalysis, 2004,227:313-327. doi: 10.1016/j.jcat.2004.07.015
[6]	Santikunaporn M, Herrera J E, Jongpatiwut S, et al. Ring opening of decalin and tetralin on HY and Pt/HY zeolite catalysts[J]. Journal of Catalysis, 2004,228:100-113. doi: 10.1016/j.jcat.2004.08.030
[7]	陈妍, 宋海涛, 朱玉霞, 等. Beta和Y型分子筛催化四氢萘裂化规律的对比[J]. 石油学报:石油加工, 2015,31(3):650-656.
[8]	Wei B, Jin L, Wang D, et al. Effect of different acid-leached USY zeolites on In-Situ catalytic upgrading of lignite tar[J]. Fuel, 2020,266:117089-117099. doi: 10.1016/j.fuel.2020.117089
[9]	Hajjar R, Millot Y, Man P P, et al. Two kinds of framework Al sites studied in BEA zeolite by X-ray diffraction,fourier transform in-frared spectroscopy,NMR techniques,and V Probe[J]. The Journal of Physical Chemistry C, 2008,112:20167-20175. doi: 10.1021/jp808356q
[10]	Wang W, Zhang W, Chen Y, et al. Mild-acid-assisted thermal or hy-drothermal dealumination of zeolite Beta,its regulation to Al dist-ribution and catalytic cracking performance to hydrocarbons[J]. Journal of Catalysis, 2018,362:94-105. doi: 10.1016/j.jcat.2018.03.002
[11]	Apelian M R, Fung A S, Kennedy G J, et al. Dealumination of zeo-lite β via dicarboxylic acid treatment[J]. The Journal of Physical Chemistry, 1996,100:16577-16583. doi: 10.1021/jp960376s
[12]	Mihályi R M, Kollár M, Király P, et al. Effect of extra-framework Al formed by successive steaming and acid leaching of zeolite MCM-22 on its structure and catalytic performance[J]. Applied Catalysis A:General, 2012,417-418:76-86. doi: 10.1016/j.apcata.2011.12.029
[13]	Huang L, Wang P, Li J, et al. Effect of acid leaching and catalytic properties of zeolite MWW utilized as ehene methylation cataly-st[J]. Microporous and Mesoporous Materials, 2016,223:230-240. doi: 10.1016/j.micromeso.2015.11.016
[14]	王成强, 欧阳颖, 罗一斌. 有机酸脱铝对β分子筛环烷烃开环反应性能的影响[J]. 石油炼制与化工, 2015,46:30-35.
[15]	Xie Z, Chen Q, Zhang C, et al. Influence of citric acid treatment on the surface acid properties of zeolite Beta[J]. The Journal of Physical Chemistry B, 2000,104:2853-2859. doi: 10.1021/jp991471e
[16]	Maache M, Janin A, Lavalley J C, et al. Acidity of zeolites beta de-aluminated by acid leaching:an FTIR.study using different probe molecules(pyridine,carbon monoxide)[J]. Zeolites, 1993,13:419-426. doi: 10.1016/0144-2449(93)90114-I
[17]	Baran R, Millot Y, Onfroy T, et al. Influence of the nitric acid treat-ment on Al removal,framework composition and acidity of BEA zeolite investigated by XRD,FTIR and NMR[J]. Microporous and Mesoporous Materials, 2012,163:122-130. doi: 10.1016/j.micromeso.2012.06.055
[18]	Dzwigaj S, Millot Y, Krafft J M, et al. Incorporation of silver atoms into the vacant T-atom sites of the framework of Si-BEA zeolite as mononuclear Ag(I) evidenced by XRD,FTIR,NMR,DR UV-vis,XPS,and TPR[J]. The Journal of Physical Chemistry C, 2013,117:12552-12559. doi: 10.1021/jp401849e
[19]	Jin Y, Xiao C, Liu J, et al. Mesopore modification of beta zeolites by sequential alkali and acidtreatments:narrowing mesopore size distribution featuring unimodality and mesoporous texture proper-ties estimated upon a mesoporous volumetric model[J]. Microporo-us and Mesoporous Materials, 2015,218:180-191.
[20]	Caillot M, Chaumonnot A, Digne M, et al. The variety of Brϕnsted acid sites in amorphous aluminosilicates and zeolites[J]. Journal of Catalysis, 2014,316:47-56. doi: 10.1016/j.jcat.2014.05.002
[21]	鞠雪艳, 胡志海, 蒋东红, 等. 金属与分子筛含量对预加氢1-甲基萘的加氢裂化催化剂的影响[J]. 石油学报:石油加工, 2012,28:711-716.
[22]	Zecevic J, Vanbutsele G, de Jong K P, et al. Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons[J]. Nature, 2015,528:245-248. doi: 10.1038/nature16173
[23]	Im J, Shin H, Jang H, et al. Maximizing the catalytic function of hy-drogen spillover in platinum-encapsulated aluminosilicates with controlled nanostructures[J]. Nature Communications, 2014,5. Doi: 10.1038/ncomms4370.
[24]	Guisnet M. “Ideal” bifunctional catalysis over Pt-acid zeolites[J]. Catalysis Today, 2013,218:123-134.

Beta分子筛	相对结晶度/%	d₃₀₂/10^-1 nm	n（SiO₂）/n（Al₂O₃）
Beta	100.0	3.941	26.0
At-Beta-1	103.1	3.952	35.6
At-Beta-2	106.5	3.962	44.0
At-Beta-3	105.6	3.962	49.6
At-Beta-4	99.8	3.940	48.2
St-Beta-1	96.4	3.941	26.0
St-Beta-2	94.4	3.940	26.0
St-Beta-3	90.7	3.941	26.0

Beta 分子筛	S_BET/ （m²·g^-1）	S_micro/ （m²·g^-1）	V_total/ （cm³·g^-1）	V_micro/ （cm³·g^-1）	V_meso/ （cm³·g^-1）
Beta	442	344	0.425	0.182	0.243
At-Beta-1	451	347	0.431	0.183	0.248
At-Beta-2	460	351	0.446	0.187	0.259
At-Beta-3	459	351	0.444	0.186	0.258
At-Beta-4	457	348	0.441	0.182	0.259
St-Beta-1	432	331	0.421	0.176	0.245
St-Beta-2	415	314	0.413	0.166	0.247
St-Beta-3	394	302	0.395	0.151	0.244

Beta 分子筛	酸量（NH₃）/ （mmol·g^-1）			酸类型及酸量（Py）/（μmol·g^-1）		B与L 酸量比
Beta 分子筛	总酸量	低温酸量	高温酸量	B	L	B与L 酸量比
Beta	0.568	0.234	0.334	128.7	77.1	1.67
At-Beta-1	0.554	0.197	0.357	132.8	54.2	2.45
At-Beta-2	0.544	0.175	0.369	144.4	33.6	4.30
At-Beta-3	0.541	0.172	0.369	148.1	34.1	4.34
At-Beta-4	0.522	0.173	0.349	130.7	32.8	3.98
St-Beta-1	0.542	0.242	0.300	106.3	134.3	0.79
St-Beta-2	0.523	0.256	0.267	78.9	139.2	0.57
St-Beta-3	0.513	0.262	0.251	67.8	126.3	0.54

Beta 分子筛	S_BET/ （m²·g^-1）	S_micro/ （m²·g^-1）	V_total / （cm³·g^-1）	V_micro / （cm³·g^-1）	V_meso / （cm³·g^-1）
Beta	442	344	0.425	0.182	0.243
At-Beta-2	460	351	0.446	0.187	0.259
St-Beta-2	415	314	0.413	0.166	0.247
At-St-Beta	425	324	0.399	0.164	0.235
St-At-Beta	449	337	0.468	0.171	0.297

Beta 分子筛	酸量（NH₃）/ （mmol·g^-1）			酸类型及酸量（Py）/（μmol·g^-1）		B与L 酸量比
Beta 分子筛	总酸量	低温酸量	高温酸量	B	L	B与L 酸量比
Beta	0.568	0.234	0.334	128.7	77.1	1.67
At-Beta-2	0.544	0.175	0.369	144.4	33.6	4.30
St-Beta-2	0.523	0.256	0.267	78.9	139.2	0.57
At-St-Beta	0.527	0.226	0.301	83.4	89.2	0.80
St-At-Beta	0.532	0.179	0.353	128.7	57.7	2.23

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