NH<sub>4</sub><sup>+</sup>交换度对CuY催化剂上甲醇氧化羰基化反应性能的影响

注册 English

NH₄⁺交换度对CuY催化剂上甲醇氧化羰基化反应性能的影响

王玉春 , 郑华艳 , 李忠

引用本文: 王玉春, 郑华艳, 李忠. NH₄⁺交换度对CuY催化剂上甲醇氧化羰基化反应性能的影响[J]. 催化学报, 2016, 37(8): 1403-1412. doi: 10.1016/S1872-2067(16)62490-7 shu

shu

Citation: Yuchun Wang, Huayan Zheng, Zhong Li. Effect of NH₄⁺ exchange on CuY catalyst for oxidative carbonylation of methanol[J]. Chinese Journal of Catalysis, 2016, 37(8): 1403-1412. doi: 10.1016/S1872-2067(16)62490-7 shu

shu

NH₄⁺交换度对CuY催化剂上甲醇氧化羰基化反应性能的影响

a. 太原理工大学, 煤科学与技术教育部和山西省重点实验室, 山西太原 030024;
b. 运城学院应用化学系, 山西运城 044000
基金项目:
国家自然科学基金（21276169）.

摘要: 碳酸二甲酯（DMC）是一种应用极其广泛的绿色化工产品，其中经济、绿色的甲醇氧化羰基化合成DMC工艺极具工业前景，而Y分子筛负载铜（CuY）是有效催化剂之一.众所周知，CuY催化剂上的Cu⁺是催化活性中心.Cu⁺催化活性中心的引入方式用两种：（1）CuCl直接与HY分子筛固相离子交换；（2）Cu²⁺与NaY分子筛溶液离子交换，然后Cu²⁺自还原生成活性中心Cu⁺.在无溶剂条件下制备CuY催化剂时，载体HY分子筛中的可交换位H⁺量是决定催化剂CuY氧化羰基化催化性能的关键因素.文献通过以不同硅铝比的HY分子筛为载体制备的催化剂CuY，研究铜离子可交换位H⁺量对氧化羰基化的影响，然而，硅铝比的不同也直接影响了分子筛骨架的组成、Si-O-Al的键角、甚至影响了Al³⁺的分散度，这些因素都直接影响了CuY催化剂活性.因此，研究NaNH₄Y分子筛载体中的可交换位（NH₄⁺）的量与CuY催化剂活性间的关系具有非常重要的意义.本文将NaY分子筛与不同浓度的NH₄NO₃溶液进行离子交换，制得具有不同NH₄⁺交换度的NaNH₄Y分子筛，以其为载体，以具有易升华、易分解性质的乙酰丙酮铜Cu（acac）₂为铜源，在无溶剂条件下，高温热处理二者固相混合物，NaNH₄Y分子筛中的NH₄⁺与Cu（acac）₂中的Cu²⁺发生了离子交换，Cu²⁺进一步发生自还原生成活性中心Cu⁺，成功地制备了完全无氯的CuY催化剂，应用于催化常压甲醇氧化羰基化合成DMC过程，研究NaNH₄Y分子筛中的铜离子可交换位NH₄⁺与催化剂CuY催化性能间的关系.通过各种表征及对CuY催化剂在甲醇氧化羰基化过程中催化活性分析发现，Y分子筛经过NH₄NO₃溶液离子交换及催化剂的制备过程，其八面沸石结构和孔道保持良好.以未经过离子交换的NaY负载的CuY催化剂上的铜物种完全以CuO形式存在，且没有催化活性.随着NH₄⁺交换度增加，CuY催化剂表面CuO含量逐渐降低，而活性中心Cu⁺含量逐渐增加，且其催化活性也随之增加.当NH₄⁺交换度趋于极限值时，CuY催化剂中Cu⁺含量达最大，其催化活性也达最佳，DMC的时空收率和选择性分别为267.3mg/（g·h）和68.5%，甲醇转化率为6.9%.因此，无溶剂条件下，以NaNH₄Y分子筛为载体，Cu（acac）₂为铜源，制备完全无氯CuY催化剂时，NH₄⁺是形成Cu⁺活性中心的必须条件，且NH₄⁺交换度直接影响催化剂CuY的催化活性.

关键词:

English

Effect of NH₄⁺ exchange on CuY catalyst for oxidative carbonylation of methanol

a. Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China;
b. Department of Applied Chemistry, Yuncheng University, Yuncheng 044000, Shanxi, China
Received Date: 04 May 2016
Revised Date: 15 June 2016
Fund Project:
This work was supported by the National Natural Science Foundation of China (21276169).

Abstract: NaY and ion exchanged NaNH₄Y zeolite with NH₄NO₃ were used as the support to prepare CuY catalysts by a high temperature anhydrous interaction between the support and copper (II) acetylacetonate Cu(acac)₂. The catalysts were used for the oxidative carbonylation of methanol to dimethyl carbonate (DMC) at atmospheric pressure. The textural and acidic properties of NaNH₄Y zeolite and the CuY catalysts were investigated by X-ray diffraction, scanning electron microscopy, N₂ adsorption-desorption, temperature programmed reduction of H₂, X-ray photoelectron spectroscopy and temperature programmed desorption of NH₃. With increasing NH₄NO₃ concentration, the NH₄⁺ exchange degree increased while the crystallinity of the zeolite remained intact. Crystalline CuO was formed when the NH₄⁺ exchange degree of NaNH₄Y was low, and the corresponding CuY catalyst showed low catalytic activity. With increasing of the NH₄⁺ exchange degree of NaNH₄Y, the content of surface bound Cu⁺ active centers increased and the catalytic activity of the corresponding CuY catalyst also increased. The surface bound Cu⁺ content reached its maximum when the NH₄⁺ exchange degree of NaNH₄Y reached towards saturation. The CuY exhibited optimal catalytic activity with 267.3 mg/(g·h) space time yield of DMC, 6.9% conversion of methanol, 68.5% selectivity of DMC.

Key words:

1. [1] M. Selva, A. Perosa, Green Chem., 2008, 10, 457-464.
2. [2] M. H. Wang, N. Zhao, Wei, Y. H. Sun, Ind. Eng. Chem Res., 2005, 44, 7596-7599.
3. [3] Y. J. Zhou, S. J.Wang, M. Xiao, D. M. Han, Y. X. Lu, Y. Z. Meng, J. Cleaner Production, 2015, 103, 925-933.
4. [4] P. Tundo, M. Selva, Acc. Chem. Res., 2002, 35, 706-716.
5. [5] S. Y. Huang, B. Yan, S. P. Wang, X. B. Ma, Chem. Soc. Rev., 2015, 44, 3079-3116.
6. [6] D. Delledonne, F. Rivetti, U. Romano, Appl. Catal. A, 2001, 221, 241-251.
7. [7] T. Frising, P. Leflaive, Microporous Mesoporous Mater., 2008, 114, 27-63.
8. [8] Y. H. Zhang, D. N. Briggs, E. de Smit, A. T. Bell, J. Catal., 2007, 251, 443-452.
9. [9] R. Y. Wang, Z. Li, H. Y. Zheng, K. C. Xie, Chin. J Catal., 2009, 30, 1068-1072.
10. [10] S. T. King, Catal. Today, 1997, 33, 173-182.
11. [11] S. T. King, J. Catal., 1996, 161, 530-538.
12. [12] Y. H. Zhang, A. T. Bell, J. Catal., 2008, 255, 153-161.
13. [13] J. Engeldinger, M. Richter, U. Bentrup, Phys. Chem. Chem. Phys., 2012, 14, 2183-2191.
14. [14] J. Engeldinger, C. Domke, M. Richter, U. Bentrup, Appl. Catal. A, 2010, 382, 303-311.
15. [15] M. Richter, M. J. G. Fait, R. Eckelt, M. Schneider, J. Radnik, D. Heidemann, R. Fricke, J. Catal., 2007, 245, 11-24.
16. [16] Z. Li, K. C. Xie, R. C. T. Slade, Appl. Catal. A, 2001, 209, 107-115.
17. [17] S. Y. Huang, Y. Wang, Z. Z. Wang, B. Yan, S. P. Wang, J. L. Gong, X. B. Ma, Appl. Catal. A, 2012, 417-418, 236-242.
18. [18] R. G. Zhang, J. R. Li, B. J. Wang, RSC Adv., 2013, 3, 12287-12298.
19. [19] Y. Kuroda, T. Mori, Y. Yoshikawa, Chem. Commun., 2001, 1006-1007.
20. [20] Y. C. Wang, H. Y. Zheng, Z. Li, K. C. Xie, RSC Adv., 2015, 5, 102323-102331.
21. [21] Y. C. Wang, H. Y. Zheng, B. Liu, G. Q. Zhang, Z. Li, Chem. J. Chin. Univ., 2015, 36, 2540-2549.
22. [22] K. Sato, Y. Nishimura, N. Matsubayashi, M. Imamura, H. Shimada, Microporous Mesoporous Mater., 2003, 59, 133-146.
23. [23] M. Richter, M. J. G. Fait, R. Eckelt, E. Schreier, M. Schneider, M. M. Pohl, R. Fricke, Appl. Catal. B, 2007, 73, 269-281.
24. [24] C. Torre-Abreu, C. Henriques, F. R. Ribeiro, G. Delahay, M. F. Ribeiro, Catal. Today, 1999, 54, 407-418.
25. [25] S. Kieger, G. Delahay, B. Coq, B. Neveu, J. Catal., 1999, 183, 267-280.
26. [26] J. W. Choung, I. S. Nam, Appl. Catal. B, 2006, 64, 42-50.
27. [27] Y. Z.Yuan, W. Cao, W. Z. Weng, J. Catal., 2004, 228, 311-320.
28. [28] X. J. Li, X. W. Zhang, L. C. Lei, Sep. Purif. Technol., 2009, 64, 326-331.
29. [29] J. M. Lázaro Martínez, E. Rodríguez-Castellón, R. M. T. Sánchez, L. R. Denaday, G. Y. Buldain, V. Campo Dall’ Orto, J. Mol. Catal. A, 2011, 339, 43-51.
30. [30] F. Alonso, T. Melkonian, Y. Moglie, M. Yus, Eur. J. Org. Chem., 2011, 2524-2530.
31. [31] Z. Li, T. J. Fu, R. Y. Wang, Y. Y. Niu, H. Y. Zheng, Chem. J. Chin. Univ., 2011, 32, 1366-1372.
32. [32] D. Liu, P. Yuan, H. M. Liu, J. G. Cai, D. Y. Tan, H. P. He, J. X. Zhu, T. H. Chen, Appl. Clay Sci., 2013, 80-81, 407-412.
33. [33] A. Sultana, T. Nanba, M. Sasaki, M. Haneda, K. Suzuki, H. Hamada, Catal. Today, 2011, 164, 495-499.
34. [34] A. Takahashi, R. T. Yang, C. L. Munson, D. Chinn,, Langmuir, 2001, 17, 8405-8413.
35. [35] G. T. Palomino, S. Bordiga, A. Zecchina, G. L. Marra, C. Lamberti, J. Phys. Chem. B, 2000, 104, 8641-8651.

WeChat

扫一扫看文章

计量

PDF下载量: 2
文章访问数: 936
HTML全文浏览量: 72

通讯作者: 陈斌, bchen63@163.com

1.
沈阳化工大学材料科学与工程学院沈阳 110142

/

下载: 全尺寸图片幻灯片

分享

用微信扫码二维码

分享至好友和朋友圈