草酸溶液处理对SAPO-34分子筛物性和催化性能的影响
收稿日期: 2019-08-29
网络出版日期: 2020-02-26
Effect of oxalic acid solution treatment on physiochemical properties and catalytic performance of SAPO-34 molecular sieve
Received date: 2019-08-29
Online published: 2020-02-26
用XRD、SEM、N2物理吸附、XRF、ICP-AES以及NH3-TPD、FT-IR、固体NMR和固定床甲醇制烯烃技术（MTO）反应评价等表征手段,研究了草酸溶液处理对SAPO-34分子筛的改性作用。结果表明,用草酸溶液对SAPO-34分子筛进行后处理可以通过刻蚀骨架在晶体中产生大孔,调变孔道结构,改善微孔扩散性能;选择性地降低分子筛的骨架硅含量,从而降低分子筛的酸强度和酸中心密度。将改性前后的分子筛应用于MTO反应中。评价结果表明,适度的酸处理能够在保证分子筛收率和乙烯、丙烯选择性的前提下,明显提高催化剂的单程寿命。草酸溶液处理是一种值得研究的SAPO-34分子筛后处理改性方法和MTO催化剂制备手段。
关键词： SAPO-34分子筛; 草酸溶液处理; MTO反应
邵武俊 , 刘春燕 , 贺宁 , 郭洪臣 . 草酸溶液处理对SAPO-34分子筛物性和催化性能的影响[J]. 无机盐工业, 2020 , 52(2) : 84 -90 . DOI: 10.11962/1006-4990.2019-0169
The modification effect of oxalic acid solution treatment on SAPO-34 molecular sieve was studied by means of XRD,SEM,N2 physisorption,XRF,ICP-AES,NH3-TPD,FT-IR,solid NMR and fixed-bed methanol to olefins（MTO） reaction performance evaluation.Results showed that,treating SAPO-34 molecular sieve with oxalic acid solution can produce macropores in the crystalsvia skeleton etching,and consequently adjust the pore structure and micropore diffusivity.Meanwhile,the acid treatment can also selectively reduce the framework Si content,and consequently decrease the acid strength and surface acid site concentrationof SAPO-34 molecular sieve.These modification effects of the oxalic acid solution treatment can notably improve the anti-coking deactivation ability of SAPO-34 catalyst in MTO reaction.Therefore,the oxalic acid solution treatment is a method worth studying for the modification of SAPO-34 molecular sieve and the preparation of MTO catalyst.
| [1] | Jin Wenlong, Wang Baojie, Guo Pengfei . Selective desilication,me-soporesformation,and MTO reaction enhancement via citric acid treatment of zeolite SAPO-34[J]. Ind.Eng.Chem.Res., 2018,57:4231-4236. |
| [2] | Valtchev V, Tosheva L . Porous nanosized particles:Preparation,pro-perties,and applications[J]. Chem.Rev., 2013,113:6734-6760. |
| [3] | De La Torre U, Pereda-Ayo B, González-Velasco J R . Cu-zeolite NH3-SCR catalysts for NOx removal in the combined NSR-SCR te-chnology[J]. Chem.Eng.J., 2012,207/208:10-17. |
| [4] | 刘中民, 刘昱, 田鹏 , 等. 甲醇制烯烃[M]. 北京: 科学出版社, 2015. |
| [5] | Di Chunyu, Li Xiaofeng, Wang Ping , et al. Green and efficient dry gel conversion synjournal of SAPO-34 catalyst with plate-like mor-phology[J]. Petroleum Science, 2017,14(1):203-213. |
| [6] | Hajfarajollah H, Askari S, Halladj R . Effects of micro and nano-sized SAPO-34 and SAPO-5 catalysts on the conversion of methanol to light olefins[J]. Reaction Kinetics Mechanisms & Catalysis, 2014,111(2):723-736. |
| [7] | Liu Guangyu, Tian Peng, Xia Qinhua , et al. An effective route to improve the catalytic performance of SAPO-34 in the methanol-to-olefin reaction[J]. Journal of Natural Gas Chemistry, 2012,21(4):431-434. |
| [8] | 任淑, 刘国娟, 吴晛 , 等. 酸处理可控制备多级孔SAPO-34及其甲醇制烯烃性能[J]. 催化学报, 2017(1):134-141. |
| [9] | Chen X X, Vicente A, Qin Z X , et al. Preparation of hierarchical SAPO-34 crystals by post-synjournal fluoride etching[J]. Chem.Co-mmun. 2016,52(17).DOI: 10.1039.C5CC09498D. |
| [10] | Qiao Y Y, Yang M, Gao B B , et al. Creation of hollow SAPO-34 single crystals via alkaline or acid etching[J]. Chemical Communi-cations, 2016,52(33):5718-5721. |
| [11] | álvaro-Mu?oz T, Márquez-álvarez C, Sastre E . Use of different te-templates on SAPO-34 synjournal:Effect on the acidity and cataly-tic activity in the MTO reaction[J]. Catalysis Today, 2012,179(1):27-34. |
| [12] | Zhong Jiawei, Han Jingfeng, Wei Yingxu , et al. Enhancing ethylene selectivity in MTO reaction by incorporating metal species in the cavity of SAPO-34 catalysts[J]. Chinese Journal of Catalysis, 2018,39(11):1821-1831. |
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