化工进展 ›› 2016, Vol. 35 ›› Issue (08): 2474-2479.DOI: 10.16085/j.issn.1000-6613.2016.08.26

• 工业催化 • 上一篇    下一篇

助剂对Pd/γ-Al2O3催化剂一步法合成二甲醚反应稳定性的影响

褚睿智1,2, 徐婷婷1, 孟献梁1,2, 吴国光1, 侯文心1   

  1. 1. 中国矿业大学化工学院, 江苏 徐州 221008;
    2. 中国矿业大学连云港徐圩新区高新技术研究院, 江苏 连云港 222000
  • 收稿日期:2016-03-21 修回日期:2016-05-24 出版日期:2016-08-05 发布日期:2016-08-05
  • 通讯作者: 褚睿智(1976—),女,博士,副教授,主要从事煤炭转化、工业催化方面研究。E-mail:xttcumt@126.com。
  • 作者简介:褚睿智(1976—),女,博士,副教授,主要从事煤炭转化、工业催化方面研究。E-mail:xttcumt@126.com。
  • 基金资助:
    国家自然科学基金(51204182)及江苏省自然科学基金(BK20141242)项目。

Influence of promoters on the stability of Pd/γ-Al2O3 catalyst for one-step synthesis of dimethylether

CHU Ruizhi1,2, XU Tingting1, MENG Xianliang1,2, WU Guoguang1, HOU Wenxin1   

  1. 1. School of Chemical Engineering, China University of Mining & Technology, Xuzhou 221008, Jiangsu, China;
    2. High-Tech Research Institute of China University of Mining and Technology, Lianyungang 222000, Jiangsu, China
  • Received:2016-03-21 Revised:2016-05-24 Online:2016-08-05 Published:2016-08-05

摘要: 采用浸渍法制备了一系列不同助剂下的负载型Pd/γ-Al2O3催化剂,考察了助剂类型对Pd/γ-Al2O3催化剂一步法合成二甲醚(STD)反应稳定性的影响规律;采用氮吸附、XRD、H2-TPR及TG等多种表征手段考察了稳定性试验前后以及烧炭再生后催化剂的表面物化性质及结构变化。结果表明,助剂成分对Pd/γ-Al2O3催化剂的STD反应稳定性影响显著。相比Pd/γ-Al2O3催化剂,添加CeO2可以提高Pd在γ-Al2O3表面的分散度,但会覆盖表面的部分酸性位,一定程度上提高了催化剂的活性和稳定性,但仍存在Pd烧结和积炭现象;添加复合助剂CeO2-ZrO2后形成的Ce-O-Zr固熔晶面能显著促进Pd均匀分散,提高催化剂的抗积炭能力和抗烧结能力,催化剂的活性和稳定性更高;经SO42-改性后Pd/γ-Al2O3催化剂会因为表面积炭加剧和表面硫流失严重,中强酸酸性位减少而快速失活。CeO2-ZrO2-Pd/γ-Al2O3催化剂经历20h的稳定性试验后CO转化率仍保持59%以上,二甲醚选择性65%以上,烧炭再生后催化活性恢复至新鲜催化剂的91.83%。

关键词: Pd/γ-Al2O3催化剂, 助剂, 制备, 稳定性, 失活, 一步法合成二甲醚, 合成气

Abstract: A series of Pd/γ-Al2O3 hybrid catalysts with different promoters were prepared by impregnation. The catalysts were used for syngas-to-dimethyl(STD)reaction and the influence of the promoters on the catalysts' stability has been investigated. Then,the surface physic-chemical properties and crystal structure of the samples before and after the stability test and coke-burning regeneration test were characterized by a variety of physical techniques,such as N2 adsorption、XRD、H2-TPR and TG. Good correlation was observed between the promoters and the stability of Pd/γ-Al2O3 catalysts for STD reaction. Compared to the original Pd/Al2O3 catalyst,the addition of promoter CeO2 had increased Pd dispersion,covered partial acid sites and inhibited carbon deposition to a certain degree,resulting in improvements on the activity and stability of the catalyst. The Ce-O-Zr crystal structure was formed when the compound promoters CeO2-ZrO2 were added,which was responsible for the increase of Pd dispersity and anti-carbon and anti-sintering ability,and therefore increased the activity and stability of the catalyst. Catalyst modified by SO42- would deactivate quickly because of serious carbon deposition,medium strong acid reduction and sulfur loss.After 20h stability test,the CO conversion and DME selectivity of CeO2-ZrO2-Pd/γ-Al2O3 were above 59% and 65%,respectively. The catalytic activity of the regenerated catalyst recovered to 91.83% of that of the fresh one.

Key words: Pd/γ-Al2O3 catalyst, promoters, preparation, stability, deactivation, syngas-to-dimethyl (STD), syngas

中图分类号: 

京ICP备12046843号-2;京公网安备 11010102001994号
版权所有 © 《化工进展》编辑部
地址:北京市东城区青年湖南街13号 邮编:100011
电子信箱:hgjz@cip.com.cn
本系统由北京玛格泰克科技发展有限公司设计开发 技术支持:support@magtech.com.cn