Co/ZrO_2和Co/Al_2O_3催化剂应用于CO_2甲烷化:实验与DFT理论计算研究
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- 英文论文题名：A Combined Experimental and Density functional theory study on Co/ZrO_2 and Co/Al_2O_3 catalysts for CO_2 methanation
- 论文作者：李文慧 ; 聂小娃 ; 宋春山 ; 郭新闻
- 英文论文作者：Wenhui Li ; Xiaowa Nie ; Chunshan Song ; Xinwen Guo ; Dalian University of Technology ; Pennsylvania State University
- 年：2016
- 作者机构：大连理工大学;宾州州立大学;
- 论文关键词：CO_2 ; 甲烷化 ; DFT理论计算 ; Co/ZrO_2 ; Co/Al_2O_3
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十五分会：表界面结构调控与催化
- 语种：中文
- 分类号：O643.36
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十五分会 ; 表界面结构调控与催化
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：148k
- 原文格式：D
- 会议级别：全国
摘要
利用等体积浸渍法制备了Co/Zr O_2和Co/Al_2O_3催化剂应用于CO_2甲烷化。10Co/Zr O_2催化剂上的CO_2转化率可以达到92.5%,CH4选择性为99.9%,并且在300小时的反应后没有失活。Co/Al_2O_3催化剂的初始CO_2转化率为71.8%,在300小时反应后,转化率下降到38.6%。利用DFT密度泛函理论对H2、CO、CH4、CO_2和NH3在两类催化剂上的吸附能和吸附位进行理论计算,发现在Co/Zr O_2催化剂上CO_2和H2的吸附要明显强于Co/Al_2O_3催化剂,这一结果与实验中的TPD结果得到了很好的吻合。对Co-O键的断裂和H*的迁移能进行理论计算,发现在Co/Zr O_2催化剂上H*更容易迁移,Co-O键更容易断裂,很好的解释了原位XRD、XPS和H2-TPR结果中Co_3O_4在Zr O_2上更容易还原这一现象。
Co/ZrO_2 and Co/Al_2O_3 catalysts with different metal loadings were prepared by impregnation method and examined for CO_2 methanation.The 10Co/Zr O_2 catalyst showed high activity with CO_2 conversion of 92.5 % and CH_4 selectivity of 99.9 % without deactivation after 300 h time on stream(TOS).However,the 10Co/Al_2O_3 catalyst gave a lower initial CO_2 conversion of 71.8 % which decreased to 38.6 % after 300 h TOS.In order to explain the essential differences,the two kinds of catalysts were characterized by in situ XRD,H2-TPR,XPS,chemisorption of H_2,CO,CH_4,and CO_2,NH_(3-)TPD,and N_2 adsorption techniques.DFT results rationalize the experimentally observed lower reduction temperature and higher reduction degree of cobalt oxide on the ZrO_2 support from in situ XRD,H_(2-)TPR and XPS.
Co/ZrO_2 and Co/Al_2O_3 catalysts with different metal loadings were prepared by impregnation method and examined for CO_2 methanation.The 10Co/Zr O_2 catalyst showed high activity with CO_2 conversion of 92.5 % and CH_4 selectivity of 99.9 % without deactivation after 300 h time on stream(TOS).However,the 10Co/Al_2O_3 catalyst gave a lower initial CO_2 conversion of 71.8 % which decreased to 38.6 % after 300 h TOS.In order to explain the essential differences,the two kinds of catalysts were characterized by in situ XRD,H2-TPR,XPS,chemisorption of H_2,CO,CH_4,and CO_2,NH_(3-)TPD,and N_2 adsorption techniques.DFT results rationalize the experimentally observed lower reduction temperature and higher reduction degree of cobalt oxide on the ZrO_2 support from in situ XRD,H_(2-)TPR and XPS.
引文
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