TMPDO和4-NOH-TMPD在HTS/H2O2催化体系中的吸附机理及对Ti—OOH的稳定作用

doi:10.7503/cjcu20150779

摘要/Abstract

摘要：

采用TG, NH₃-TPD, FTIR和原位IR考察分析了2,2,6,6-四甲基-4-酮-哌啶(TMPDO)和2,2,6,6-四甲基-4-肟基-哌啶(4-NOH-TMPD)在空心钛硅分子筛/双氧水(HTS/H₂O₂)体系中的吸附作用和机理. 结果表明, HTS/H₂O₂体系中的催化剂表面存在Si—OH和Ti—OOH活性位; TMPDO和4-NOH-TMPD分子主要通过碱性的═N—H基与酸性较强的Si—OH中心作用, 同时分子中对位的羰基或肟基与Ti—OOH中心作用, 形成双位吸附. 从而显著地提高活性中心Ti—OOH的稳定性和浓度, 并导致催化剂表面强酸位数量明显减少, 而弱酸位数量明显增加. 因此, 通过吸附适当有机碱来修饰催化剂的表面性质, 可以提高HTS/H₂O₂体系的催化活性和选择性.

关键词: 空心钛硅分子筛/双氧水体系, 2,2,6,6-四甲基-4-酮-哌啶, 2,2,6,6-四甲基-4-肟基-哌啶, 吸附机理

Abstract:

The adsorption mechanisms of 2,2,6,6-tetramethyl-piperdin-4-one(TMPDO) and 2,2,6,6-tetramethyl-piperdin-4-one-oxime(4-NOH-TMPD) in HTS/H₂O₂ system were investigated by thermogravimetry analysis(TG), NH₃ temperature programmed desorption(NH₃-TPD), Fourier transform infrared spectrum(FTIR) and in situ IR. The results showed that there were Si—OH and Ti—OOH active sites on the surface of the catalyst in HTS/H₂O₂ system. Two-site adsorption was formed by the interaction of alkali group ═N—H of TMPDO or 4-NOH-TMPD with strong acid center Si—OH, and para group —C═O in TMPDO or —N═OH in 4-NOH-TMPD with Ti—OOH center. Such two-center adsorption of TMPDO or 4-NOH-TMPD on surface of HTS significantly increased the stability and concentration of active site Ti—OOH in HTS/H₂O₂ system, and thus caused an evident decrease of strong acid sites and an increase of weak acid sites on surface of the catalyst. Therefore, it is expected to improve the catalytic activity and selectivity of HTS/H₂O₂ system by modifying the surface properties of catalyst with adsorption of appropriate organic bases.

Key words: HTS/H2O2, 2,2,6,6-Tetramethyl-piperdin-4-one(TMPDO), 2,2,6,6-Tetramethyl-piperdin-4-one-oxime(4-NOH-TMPD), Adsorption mechanism

中图分类号:

O643.31

TrendMD:

严山, 张胜建, 赵迎宪, 李显明, 张永明, 张洪, 王健, 符建琼. TMPDO和4-NOH-TMPD在HTS/H₂O₂催化体系中的吸附机理及对Ti—OOH的稳定作用. 高等学校化学学报, 2016, 37(5): 946.

YAN Shan, ZHANG Shengjian, ZHAO Yingxian, LI Xianming, ZHANG Yongming, ZHANG Hong, WANG Jian, FU Jianqiong. Adsorption Mechanisms of TMPDO and 4-NOH-TMPD in HTS/H₂O₂System and Effects on the Stabilization of Ti—OOH^†. Chem. J. Chinese Universities, 2016, 37(5): 946.

图/表 16

Scheme 1 Structures of surface active sites in TS-1/H2O2 system

Scheme 2 Cyclic structure formed by methanol and Ti—OOH interaction in TS-1/H2O2 system

Scheme 3 Stable structure formed by interaction of KH2PO4 and Ti-OOH in TS-1/H2O2 system

Fig.1 TG curves of different systemsa. HTS/H2O2, 0.1 g HTS and 10 g H2O2; b. HTS/H2O/TMPDO, 0.1 g HTS, 10 g H2O and 0.1 g TMPDO; c. HTS/H2O/4-NOH-TMPD, 0.1 g HTS, 10 g H2O and 0.1 g 4-NOH-TMPD; d. HTS/H2O2/TMPDO, 0.1 g HTS, 10 g H2O2, and 0.1 g TMPDO; e. HTS/H2O2/4-NOH-TMPD, 0.1 g HTS, 10 g H2O2, and 0.1 g 4-NOH-TMPD; f. HTS/H2O, 0.1 g HTS and 10 g H2O.

Table 1 Mass loss of different systems

System	Mass loss, w(%)
System	100—200 ℃	200—400 ℃	400—700 ℃	Total
HTS/H₂O	0.1	0.1	0	0.2
HTS/H₂O₂	0.2	0.3	0	0.5
HTS/H₂O/TMPDO	1.7	1.3	0.4	3.4
HTS /H₂O/4-NOH-TMPD	2.8	2.6	0.4	5.8
HTS/H₂O₂/TMPDO	5.4	5.1	0.8	11.3
HTS /H₂O₂/4-NOH-TMPD	7.0	4.0	0.6	11.6

Scheme 4 Ti—OH(B3) and Si—OH(B1) formed by H2O adsorption on TS-1

Scheme 5 Active sites Ti—OOH(B2) and Si—OH(B1) formed by the adsorption of H2O2/H2O on HTS

Fig.2 Infrared spectra, pyridine absorbed in HTS(a) and HTS/H2O2(b) system with vacuum <1 Pa, pretreatment at 70 ℃ for 1 h

Table 2 Molar adsorption quantity of vasious sytems

System	Adsorbate	R_wl(%)	c_ad/(μmol·g^-1)	Adsorption rate^*(%)
HTS/H₂O	H₂O	0.2	111	12
HTS/H₂O₂	H₂O+H₂O₂	0.5	147	16
HTS/H₂O/TMPDO	H₂O+TMPDO	3.4	203	22
HTS/H₂O/4-NOH-TMPD	H₂O+4-NOH-TMPD	5.8	328	36
HTS/H₂O₂/TMPDO	H₂O+H₂O₂+TMPDO	11.3	674	74
HTS/H₂O₂/4-NOH-TMPD	H₂O+H₂O₂+4-NOH-TMPD	11.6	643	71

Fig.3 FTIR spectra of HTS(a), HTS/H2O2(b), HTS/H2O2/TMPDO(c) and HTS/H2O2/4-NOH-TMPD(d) with different mass ratios of HTS/4-NOH-TMPD(e, f)Sample compositions:a. 0.1 g HTS; b. 0.1 g HTS, 10 g H2O2; c. 0.1 g HTS, 10 g H2O and 0.1 g TMPDO; d. 0.1 g HTS, 10 g H2O and 0.01 g 4-NOH-TMPD; e. 0.1 g HTS, 10 g H2O2 and 0.05 g TMPDO; f. 0.1 g HTS, 10 g H2O2 and 0.1 g 4-NOH-TMPD.

Fig.4 NH3-TPD profiles of HTS(a), HTS/H2O(b), HTS/H2O2(c), HTS/H2O2/TMPDO(d) and HTS/H2O2/4-NOH-TMPD(e)Sample compositions: a. 0.1 g HTS; b. 0.1 g HTS and 10 g H2O; c. 0.1 g HTS and 10 g H2O2; d. 0.1 g HTS, 10 g H2O2 and 0.1 g TMPDO; e. 0.1 g HTS, 10 g H2O2 and 0.1 g 4-NOH-TMPD.

Table 3 Acid strength distribution of HTS in different mediums measured by NH3-TPD

Temperature/℃	Acidity/(μmol·g^-1)
Temperature/℃	HTS	HTS/H₂O	HTS/H₂O₂	HTS/H₂O₂/TMPDO	HTS/H₂O₂/4-NOH-TMPD
150—200	78	23	157	389	432
200—250	10	63	165	120	64
250—300	0	82	124	47	28
300—350	0	0	75	0	0
Total	88	168	521	556	524

Fig.5 IR spectra of HTS/H2O2 sample after TMPDO adsorption at 70 ℃ followed by desorption in vacuum(<1 Pa) at different temperatures(A) 1300—1800 cm-1. a. 80 ℃; b. 150 ℃; c. 200 ℃; d. 300 ℃; e. 350 ℃.(B) 2800—3800 cm-1. a. 80 ℃; b. 150 ℃; c. 200 ℃; d. 250 ℃; e. 300 ℃; f. 350 ℃.

Fig.6 IR spectra of HTS/H2O2 sample after 4-NOH-TMPD adsorption at 70 ℃ followed by desorption in vacuum(<1 Pa) at different temperatures(A) 1300—1800 cm-1; (B) 2800—3800 cm-1. a. 70 ℃; b. 150 ℃; c. 200 ℃; d. 250 ℃; e. 300 ℃; f. 350 ℃.

Scheme 6 Model of two-center adsorption in HTS/H2O2/TMPDO system

Scheme 7 Two different models of two-site adsorption in HTS/H2O2/4-NOH-TMPD system

参考文献 29

[1]	Taramasso M., Perego G., Notari B., Preparation of Porous Crystalline Synthetic Material Comprised of Silicon and Titanium Oxides, US Patent 4410501, 1983-10-18
[2]	Bhaumik A., Mukherjee P., Kumar R., J. Catal., 1998, 178(1), 101—107
[3]	Bengoa J. F., Gallegos N. G., Marchetti S. G., Alvarez A. M., Cagnoli M. V., Yeramian A. A., Microporous MesoporousMater., 1998, 24(4—6), 163—172
[4]	Le Bars J., Dakka J., Sheldon R. A., Appl. Catal. A:Gen., 1996, 136(1), 69—80
[5]	Tatsumi T., Jappar N., J. Catal., 1996, 161(2), 570—576
[6]	Shi C. F., Zhu B., Lin M., Long J., Wang R. W., Catal.Today, 2011, 175(1), 398—403
[7]	Chen R. Z., Bu Z., Li Z. H., Zhong Z. X., Jin W. Q., Xing W. H., Chem. Eng.J., 2010, 156(14), 418—422
[8]	Zheng A. G., Xia C. J., Xiang Y. J., Xin M. D., Zhu B., Lin M., Xu G. T., Shu X. T., Catal.Commun., 2014, 45, 34—38
[9]	Bordiga S., Bonino F., Damin A., Lamberti C., Phys. Chem. Chem.Phys., 2007, 9(35), 4854—4878
[10]	Spanó E., Tabacchi G., Gamba A., Fois E., J. Phys. Chem.B, 2006, 110(43), 21651—21661.
[11]	Panyaburapa W., Nanok T., Limtrakul J., J. Phys. Chem.C, 2007, 111(8), 3433—3441
[12]	Wang L. L., Xiong G., Su J., Li P., Guo H. C., J. Phys. Chem.C, 2012, 116(16), 9122—9131
[13]	Yoon C. W., Hirsekorn K. F., Neidig M. L.,Yang X. Z., Tilley T. D., ACSCatal., 2011, 1(12), 1665—1678
[14]	Cordeiro P. J., Tilley T. D., ACSCatal., 2011, 1(5), 455—467
[15]	Wang Y., Zhang S. J., Zhao Y. X., Lin M., J. Mol. Catal. A: Chem., 2014, 385, 1—6
[16]	Tozzola G., Mantegazza M. A., Ranghino G., Petrini G., Bordiga S., Ricchiardi G., Lamberti C., Zulian R., Zecchina A., J. Catal., 1998, 179(1), 64—71
[17]	Zhuang J. Q., Yan Z. M., Liu X. M., Liu X. C., Han X. W., Bao X. H., Mueller U., Catal.Lett., 2002, 83(1/2), 87—91
[18]	Zhu Y. X., Lin W., Tian H. P., Long J., PetrochemicalTechnol., 2006, 35(7), 607—614
	(朱玉霞, 林伟, 田辉平, 龙军. 石油化工, 2006, 35(7), 607—614)
[19]	Li H., Lei Q., Zhang X. M., Suo J. S., Chinese J.Catal., 2013, 34(7), 1363—1372
	(李颢,雷骞,张小明,索继栓.催化学报, 2013, 34(7), 1363—1372)
[20]	Li H., Lei Q., Zhang X. M., Suo J. S., Microporous MesoporousMater., 2012, 147(1), 110—116
[21]	Katada N., Niwa M., Catal. Surv.Asia, 2004, 8, 161—170
[22]	Prakash A. M., Sung-Suh H. M., Kevan L., J. Phys. Chem.B, 1998, 102(5), 857—864
[23]	Yang G., Zhou L. J., Han X. W., J. Mol. Catal. A: Chem., 2012, 363/364, 371—379
[24]	Liu W. H., Guo P., Su J., Hu J., Wang Y. M., Liu N., Guo H. C., Chinese J.Catal., 2009, 30(6), 482—484
	(刘文欢, 郭鹏, 苏际, 胡佳, 王艳梅, 刘娜, 郭洪臣. 催化学报, 2009, 30(6), 482—484)
[25]	Zakrzewski J., Monatsh. Chem. ChemicalMonthly, 1990, 121(10), 803—808
[26]	Bordiga S., Damin A., Bonino F., Zecchina A., Spanò G., Rivetti F., Bolis V., Prestipino C., Lamberti C., J. Phys. Chem.B, 2002, 106(38), 9892—9905
[27]	Rozantsev E. G., Chudinov A. V., Sholle V. D., Bull. Acad. Sci. USSR Div. Chem. Sci., 1980, 29(9), 1510—1513
[28]	Liu H. J., Liu P. L., You K. Y., Luo H. A., Catal.Commun., 2010, 11(10), 887—891
[29]	Krinitskaya L. A., Volodarskii L. B., Bull. Acad. Sci. USSR Div. Chem. Sci., 1983, 32(2), 352—355

TMPDO和4-NOH-TMPD在HTS/H₂O₂催化体系中的吸附机理及对Ti—OOH的稳定作用

Adsorption Mechanisms of TMPDO and 4-NOH-TMPD in HTS/H₂O₂System and Effects on the Stabilization of Ti—OOH^†

RichHTML

PDF (PC)

可视化

摘要/Abstract

引用本文

使用本文

图/表 16

参考文献 29

相关文章 8

编辑推荐

Metrics

本文评价

[1]	李敏, 赵纯, 冯钦忠, 冯建, 孟晓静. 硫脲基纳米螯合纤维对水溶液中Cd(Ⅱ)的吸附和密度泛函理论计算[J]. 高等学校化学学报, 2021, 42(12): 3680.
[2]	李博文,汪若蘅,黎丽,肖杨. 碱活化多孔碳用于分离甲苯及活化/吸附机理[J]. 高等学校化学学报, 2020, 41(2): 284.
[3]	栾敬德, 刘亚伟, 张成玉, 可欣. 蒙脱石复合材料对Zn²⁺和对硝基苯酚的同步捕集[J]. 高等学校化学学报, 2018, 39(2): 270.
[4]	王小兵, 石秀仪, 周星均, 丘秀珍, 卢文贯. 金属-有机骨架材料NH₂-MIL-53(Al)对水中双氯芬酸钠的吸附性能[J]. 高等学校化学学报, 2018, 39(2): 206.
[5]	肖小雨, 盛光遥, 邱宇平. 海水体系中黑碳吸附三丁基锡的行为与机理[J]. 高等学校化学学报, 2013, 34(1): 84.
[6]	李纪红,张原玮,杨眉,张静,马翼,袁直 . 寡肽吸附剂的制备及吸附机理[J]. 高等学校化学学报, 2008, 29(6): 1159.
[7]	李纪红,俞玫,王慧彦,袁直,马翼 . 计算机模拟内毒素吸附剂吸附机理的研究[J]. 高等学校化学学报, 2006, 27(6): 1066.
[8]	钱建刚, 吴锦屏, 顾惕人. 非离子表面活性剂的吸附机理和表面胶团化对二氧化硅悬浮液稳定性的影响[J]. 高等学校化学学报, 1996, 17(6): 933.