高等学校化学学报 ›› 2013, Vol. 34 ›› Issue (9): 2171.doi: 10.7503/cjcu20130285

• 物理化学 • 上一篇    下一篇

水凝胶法制备Ni/ZrO2催化剂及催化CO2加氢甲烷化性能

刘泉, 任军, 秦志峰, 苗茂谦, 李忠   

  1. 太原理工大学煤科学与技术教育部和山西省重点实验室, 太原 030024
  • 收稿日期:2013-03-27 出版日期:2013-09-10 发布日期:2013-08-30
  • 作者简介:任军,男,博士,副教授,主要从事一碳化学和多相催化研究.E-mail:renjun@tyut.edu.cn
  • 基金资助:

    国家“九七三”计划项目(批准号:2012CB723105);山西省自然科学基金(批准号:2010011014-5);山西省科技攻关项目(批准号:20120313005-1);山西省高等学校优秀青年学科带头人支持计划项目[晋教科(2010)4号]资助.

Catalytic Performance of the Ni/ZrO2 Catalysts Prepared with the Hydrogel Method in Methanation of CO2

LIU Quan, REN Jun, QIN Zhi-Feng, MIAO Mao-Qian, LI Zhong   

  1. Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, China
  • Received:2013-03-27 Online:2013-09-10 Published:2013-08-30

摘要:

采用水凝胶法制备出一系列Ni/ZrO2催化剂, 使用X射线衍射(XRD), 比表面积(BET)测试, 透射电子显微镜(TEM)和氢气程序升温还原(H2-TPR)对其结构进行了表征, 并考察了在CO2加氢甲烷化反应中的催化活性. 研究结果表明, 经过450 ℃焙烧的催化剂中ZrO2呈无定形结构, NiO均匀分散在ZrO2表面上; 在400 ℃时H2还原过程中, 部分无定形ZrO2转变为四方晶相结构并使Ni再次分散, Ni与ZrO2之间的电子作用抑制了Ni晶粒的生长和ZrO2晶型的转变; 与无定形ZrO2和四方相ZrO2产生电子作用的NiO对催化剂活性起决定性作用, 当Ni/Zr摩尔比为0.707时, 催化剂活性最高. 在H2/CO2体积比为4, 空速为1×104 h-1, 压力为0.5 MPa, 反应温度为200 ℃时, CO2转化率达到27%以上, 当反应温度上升至280~320 ℃时, CO2转化率达到99%以上, CH4选择性大于92%.

关键词: Ni/ZrO2催化剂, 二氧化碳, 甲烷化, 水凝胶法

Abstract:

A series of Ni/ZrO2 catalysts was prepared by the hydrogel method and characterized by X-ray diffraction(XRD), Brunauer-Emmett-Tetter(BET), transmission electron microscopy(TEM) and H2 temperature programmed reduction(H2-TPR), and their catalytic activities for the methanation of carbon dioxide were investigated. The results show that ZrO2 presents an amorphous structure in the Ni/ZrO2 catalysts after calcination at 450℃. During the H2 reduction at the temperature of 400 ℃, the amorphous ZrO2 carrier was partly transformed into tetragonal phase and Ni species were re-dispersed on the surface of ZrO2. The metal-support interaction restrains the growth of NiO and ZrO2, and electron cavity on amorphous ZrO2 carrier favors the dispersion of Ni species. The NiO species interacted with amorphous ZrO2 and tetragonal ZrO2 has a definitive effect on the catalytic performance of the Ni/ZrO2 catalysts. The highest catalytic activity was obtained on the Ni/ZrO2 catalyst with a Ni/Zr molar ration of 0.707. Under the reaction condition, V(CO2)/V(H2)=1/4, gaseous hourly space velocity(GHSV)=1×104 h-1, P=0.5 MPa, 27% CO2 conversion was obtained at a low temperature of 200 ℃. The conversion of CO2 reached above 99% with the selectivity of CH4 above 92% when the reaction temperature was improved to 280—320 ℃.

Key words: Ni/ZrO2 catalyst, CO2, Methanation, Hydrogel method

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