化工学报 ›› 2021, Vol. 72 ›› Issue (10): 5183-5195.DOI: 10.11949/0438-1157.20210506

• 催化、动力学与反应器 • 上一篇    下一篇

失活TS-1高效催化C4=裂解制C3=反应的研究

黄鑫(),林玉霞,阎炳会,刘月明()   

  1. 华东师范大学化学与分子工程学院,上海市绿色化学与化工过程绿色化重点实验室,上海 200062
  • 收稿日期:2021-04-13 修回日期:2021-07-04 出版日期:2021-10-05 发布日期:2021-10-05
  • 通讯作者: 刘月明
  • 作者简介:黄鑫(1995—),男,硕士研究生,1010803690@qq.com
  • 基金资助:
    国家自然科学基金项目(22072044)

Deactivated TS-1 as an efficient catalyst for catalytic cracking of butene to propene

Xin HUANG(),Yuxia LIN,Binghui YAN,Yueming LIU()   

  1. Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
  • Received:2021-04-13 Revised:2021-07-04 Online:2021-10-05 Published:2021-10-05
  • Contact: Yueming LIU

摘要:

低碳烯烃(C4=/C5=)催化裂解生成高附加值产物C3=,同时实现C4/C5资源的高效利用,具有重要的研究意义和工业应用价值。高选择性生成烯烃类产物,尤其是目标产物C3=,同时减少非烯烃类副产物的产生,是C4=催化裂解技术发展的重要方向,其核心在于高效催化剂的研制。目前工业催化剂主要是改性的ZSM-5。钛硅分子筛TS-1是工业环己酮液相氨肟化过程中的高效催化剂,其失活后显示出典型的Br?nsted酸性质,基于此,发展了失活TS-1作为催化剂高效催化C4=裂解制C3=的方法,结果表明,失活TS-1经酸洗处理和K+交换修饰后,显示出高活性、高选择性和高稳定性的特征。进一步研究显示,失活TS-1的催化裂解活性中心为呈Br?nsted酸性的、与钛羟基相邻的硅羟基(Si—OH(Ti)),该酸中心结构不同于ZSM-5的骨架桥式铝羟基(Si—(OH)—Al),表现出相对较弱的酸强度特征,因而促进了C4=催化裂解生成C3=的主反应路径,抑制了氢转移副反应路径。失活TS-1催化剂Br?nsted酸中心的发展与应用为废催化剂固废资源的资源化利用提供了新思路。

关键词: 失活, 催化剂, 催化, Br?nsted酸中心, 氢转移反应

Abstract:

Catalytic cracking of light olefins (C4=/C5=) can produce high value-added product C3=, meanwhile achieve efficient utilization of C4/C5 resources, which has very important research significance and industrial application value. The main technical problem of catalytic cracking of C4= is how to obtain high selectivity of olefin products, especially the target product C3= and to reduce non-olefin by-products, and its core lies in the development of high-efficiency catalysts. At present, the main industrial catalyst is modified ZSM-5. Titanium silicate molecular sieve TS-1 is a high-efficiency catalyst in the liquid phase ammoximation process of industrial cyclohexanone , which shows a typical Br?nsted acid property after deactivation. Based on this, the deactivated TS-1 as an efficient catalyst for catalytic cracking of C4= to produce C3= was developed, and the result indicated that the deactivated TS-1 after acid treatment and potassium ion (K+) exchange could show the feature of high activity, high selectivity and high stability. Combined with nitric acid treating modification, K+ exchange experiment and the characterization techniques such as UV-Vis (UV-visible spectroscopy), FT-IR (Fourier transform infrared spectrometer) and NH3-TPD (temperature-programmed desorption of ammonia), it was found that the catalytic cracking active center of deactivated TS-1 is Br?nsted acidic silyl hydroxyl group (Si—OH(Ti)) adjacent to the titanium hydroxyl group. The structure of this Br?nsted acid site is completely different from the skeleton bridge Br?nsted acid site (Si—(OH)—Al) of ZSM-5, meanwhile shows relatively weak acid strength. The unique acid property of Si—OH(Ti) could promote the main reaction path of catalytic cracking of C4= to produce C3= and inhibit the side reaction path of hydrogen transfer reaction. The discovery and application of the special Br?nsted acid center of the deactivated TS-1 waste catalyst can provide a new idea for resource utilization of solid waste resources of spent catalyst.

Key words: deactivation, catalyst, catalyze, Br?nsted acid site, hydrogen transfer reaction

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