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研究论文

氮改性ZnO-ZrO2/SBA-15催化剂的酸碱性与其催化乙醇合成1,3-丁二烯反应性能的关系

薛冰a, 关伟鑫a, 王鹏a, 侯少文a, 陈欣辉a, 王奕星a, 苟焕其a, 郭锋浩a, 王梦闯a, 王天姿a, 刘金德a, 郑洲b, 柴寿根b, 陈家锐b, 张建林c, 棘云飞c, 倪珺a,*   

  1. a绿色化学合成技术国家重点实验室培育基地,浙江工业大学,杭州,中国;
    b浙江普康化工有限公司,开化,中国;
    c嘉兴南洋万事兴化工有限公司,嘉兴,中国
  • 投稿日期:2023-10-28

Relationship between the acid-base properties of nitrogen-modified ZnO-ZrO2/SBA-15 catalysts and their catalytic performance in the synthesis of 1,3-butadiene from ethanol

  • Received:2023-10-28
  • Contact: Email: junni@zjut.edu.cn

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1,3-丁二烯（以下简称丁二烯）作为化工的重要有机中间体,在石油以及橡胶工业有着广泛的用途。以乙醇为原料生产丁二烯能够解决生产原料不可再生的问题,所以受到越来越多的关注。本文采用SBA-15为载体,硝酸盐为氧化物前驱体,含氮有机物为助剂,通过水热合成法制备了催化剂,并探究了乙醇合成丁二烯反应过程中,乙醇转化率、丁二烯收率与催化剂酸碱性的关系。具体来说,在Zn-Zr/SBA-15催化剂的基础上,使用三聚氰胺（M）、三聚氰酸（Ma）、1,10-菲啰啉（Pm）、咪唑（Im）和1,3,5-三嗪（St）对催化剂进行改性。通过对催化剂的活性评价,计算得到乙醇脱氢和脱水、乙醛缩合、MPV反应的活性。根据反应活性和丁二烯收率与催化剂酸碱性（催化剂的酸碱强度和含量）的变化关系,我们发现适当数量的弱酸（0.026 mmol·g-1）、中酸（0.070 mmol·g-1）、中碱（0.052 mmol·g-1）和强碱（0.052 mmol·g-1）有助于乙醇脱氢反应的发生,过量的弱酸和中酸将导致乙醇的脱水反应。中等数量的中酸（0.070 mmol·g-1）和中碱（0.055 mmol·g-1）有利于乙醛缩合和MPV反应的发生。丁二烯收率与乙醛缩合活性和MPV活性关联较大。三聚氰胺改性的催化剂（Zn-Zr/SBA-15+M）的弱酸、中酸、中碱和强碱含量符合以上的最优数量,因此催化性能最优异：乙醇转化率为99.5%,丁二烯选择性为65.5%,丁二烯产能达到了0.45 gBD·g-1 cat·h-1。

关键词: 氮改性, ZnO-ZrO2, 酸碱性, 乙醇, 丁二烯

1,3-Butadiene (hereinafter referred to as butadiene), as an important organic intermediate in the chemical industry, has a wide range of uses in the petroleum and rubber industries. Using ethanol as raw material to produce butadiene can solve the non-renewable problem of raw materials, so it has received more and more attention. In this paper, catalysts were hydrothermally synthesized by using SBA-15 as the support, nitrate as the oxide precursor, and nitrogen-containing organic compounds as the additive. And then, the relationship between catalytic performance (ethanol conversion and butadiene yield) and the acid-base properties of catalysts was explored in the synthesis of butadiene from ethanol. Specifically, we used melamine (M), cyanuric acid (Ma), 1,10-phenanthroline (Pm), imidazole (Im), and 3,5-triazine (St) as nitrogen-containing additives during the preparation of Zn-Zr/SBA-15-X catalysts. Through the activity evaluation of the catalysts, the activities of ethanol dehydrogenation and dehydration, acetaldehyde condensation, and MPV reactions were calculated. Then, by analyzing the dependence of these activities and butadiene yield on the acidity and basicity (the strength and number of acidic/basic sites) of catalysts, we found that appropriate amounts of weak acid (0.026 mmol·g-1), medium acid (0.070 mmol·g-1), medium base (0.052 mmol·g-1), and strong base (0.056 mmol·g-1) are helpful for the ethanol dehydrogenation, whereas excess amount of weak acid and medium acid will lead to the ethanol dehydration. Moderate amounts of medium acid (0.070 mmol·g-1) and medium base (0.055 mmol·g-1) will favor the acetaldehyde condensation and MPV reactions. The butadiene yield is closely related to the activities of acetaldehyde condensation and MPV. The melamine-modified catalyst (Zn-Zr/SBA-15+M) has the optimum amounts of weak acid, medium acid, medium base, and strong acid in accordance with the above quantities, resulting in the best catalytic performance: 99.5% conversion of ethanol, 65.5% selectivity of butadiene, and 0.45 gBD·g-1 cat·h-1 of butadiene productivity.

Key words: Nitrogen modification, ZnO-ZrO2, Acid-base properties, Ethanol, Butadiene