二氧化铈促进钴氧化物表面氧化一氧化碳的原位表征研究（英文）
|
摘要
CO氧化由其广泛的应用而成为催化领域中研究的重要反应,Co_3O_4催化剂具有价格低廉、催化活性高等优点而引起研究者的关注,其中,催化剂的结构、表面特性及反应机理等是研究的重点.催化剂的原位研究对观察相变过程,理解相应的表面化学反应和反应机理起着重要的作用.本文采用煅烧法制备了Ce O_2掺杂的Co_3O_4,并对其催化CO氧化反应性能进行了研究.通过扫描电镜、高分辨率透射电镜、拉曼光谱和X射线光电子能谱对催化剂的微观结构和形态进行了表征.通过原位X射线衍射(原位XRD)和原位漫反射红外傅立叶变换光谱(原位DRIFTS)表征了Ce O_2掺杂Co_3O_4对CO氧化的效果.原位XRD测试是在氢气气氛中进行,借以评估催化剂的氧化还原特性.结果表明,由于Ce O_2的补氧能力,CeO_2掺杂可以提高Co~(2+)的还原能力,并促进了Co~(3+)-Co~(2+)-Co~(3+)循环.采用原位DRIFTS对CeO_2改性的Co_3O_4表面吸附的碳酸盐物种进行了探究.结果表明,吸附碳酸盐物种的CeO_2掺杂Co_3O_4催化剂的红外峰与纯Co_3O_4相比有所不同.CeO_2掺杂的Co_3O_4上吸附的碳酸盐物种较为活泼,其与催化剂表面的结合作用力比较弱,不会覆盖催化剂表面的活性位点,能有效抑制催化剂的失活.本文揭示了CeO_2掺杂Co_3O_4促进CO氧化的机理,为设计高效氧化CO的催化剂提供了理论支持.原位XRD的结果表明,由于CeO_2的补氧能力,引入CeO_2可以显著提高Co~(2+)的稳定性.换句话说,它可以通过降低Co~(2+)的氧化能力来提高Co~(2+)的还原能力,有利于促进Co~(3+)-Co~(2+)-Co~(3+)循环的稳定性,从而使Co~(2+)更容易转化为Co~(3+).原位DRIFTS表明,在某种程度上,吸附在CeO_2-Co_3O_4表面的碳酸盐物种呈游离态,与催化剂表面的结合作用力较弱.这种类型的碳酸盐更活泼,而且不会像那些强作用在催化剂表面的碳酸盐物种那样使表面钝化.CeO_2-Co_3O_4与Co_3O_4的表面吸附的碳酸盐物种的差异是由于引入的CeO_2对氧化钴表面进行修饰改性的结果.在高温和N_2气氛下进行预处理后,CeO_2表面变得光洁且形成了一些氧空位,其特殊的储氧能力通过弱吸附氧使其表面更加活泼.这些结果证实,经过CeO_2的修饰后,氧化钴表面更加活泼,且更适合CO氧化反应的发生.
In situ studies of catalysts play valuable roles in observing phase transformation,understanding the corresponding surface chemistry and the mechanism of the reaction.In this paper,ceria promoted cobalt oxide was prepared by the calcination method and investigated for the CO oxidation.The microstructure and morphology of CeO_2-Co_3O_4 were investigated by the Scanning Electron Microscope,High-resolution transmission electron microscopy,Raman and X-ray photoelectron spectroscopy characterization.The effect of CeO_2 doping on Co_3O_4 for CO oxidation was characterized by in situ X-ray Diffraction(in situ XRD)and in situ diffuse reflectance infrared Fourier transform spectroscopy(in situ DRIFTS).In situ XRD was carried out under H_2 atmosphere to evaluate the redox property of catalysts.The results indicated that the ceria doping can enhance the reducibility of Co~(2+) and promote the Co~(3+)—Co~(2+)—Co~(3+) cycle,owing to the oxygen replenish property of CeO_2.Furthermore,adsorbed carbonate species on the surface of Ce O_2-Co_3O_4 were investigated by in situ-DRIFTS experiment.It was turned out that carbonate species on ceria promoted cobalt oxide catalysts showed different IR peaks compared with pure cobalt oxide.The carbonate species on ceria promoted catalyst are more active,and similar to free state carbonate species with weak bonding to catalyst surface,which can effectively inhibit catalyst inactivation.This study revealed the mechanism of ceria promoting CO oxidation over cobalt oxide,which will provide theoretical support for the design of efficient CO oxidation catalysts.
In situ studies of catalysts play valuable roles in observing phase transformation,understanding the corresponding surface chemistry and the mechanism of the reaction.In this paper,ceria promoted cobalt oxide was prepared by the calcination method and investigated for the CO oxidation.The microstructure and morphology of CeO_2-Co_3O_4 were investigated by the Scanning Electron Microscope,High-resolution transmission electron microscopy,Raman and X-ray photoelectron spectroscopy characterization.The effect of CeO_2 doping on Co_3O_4 for CO oxidation was characterized by in situ X-ray Diffraction(in situ XRD)and in situ diffuse reflectance infrared Fourier transform spectroscopy(in situ DRIFTS).In situ XRD was carried out under H_2 atmosphere to evaluate the redox property of catalysts.The results indicated that the ceria doping can enhance the reducibility of Co~(2+) and promote the Co~(3+)—Co~(2+)—Co~(3+) cycle,owing to the oxygen replenish property of CeO_2.Furthermore,adsorbed carbonate species on the surface of Ce O_2-Co_3O_4 were investigated by in situ-DRIFTS experiment.It was turned out that carbonate species on ceria promoted cobalt oxide catalysts showed different IR peaks compared with pure cobalt oxide.The carbonate species on ceria promoted catalyst are more active,and similar to free state carbonate species with weak bonding to catalyst surface,which can effectively inhibit catalyst inactivation.This study revealed the mechanism of ceria promoting CO oxidation over cobalt oxide,which will provide theoretical support for the design of efficient CO oxidation catalysts.
引文
[1]L.Wang,X.Lu,W.Wang,W.Zhan,Y.Guo,Y.Guo,Chin.J.Catal.,2018,39,1560-1567.
[2]X.Xie,Y.Li,Z.Q.Liu,M.Haruta,W.Shen,Nature,2009,458,746-749.
[3]M.J.Pollard,B.A.Weinstock,T.E.Bitterwolf,P.R.Griffiths,A.P.Newbery,J.B.Paine III,J.Catal.,2008,254,218-225.
[4]J.Jansson,A.E.C.Palmqvist,E.Fridell,M.Skoglundh,L.?sterlund,P.Thorm?hlen,V.Langer,J.Catal.,2002,211,387-397.
[5]L.F.Liotta,G.Di Carlo,G.Pantaleo,G.Deganello,Catal.Commun.,2005,6,329-336.
[6]A.Trovarelli,C.de Leitenburg,M.Boaro,G.Dolcetti,Catal.Today.,1999,50,353-367.
[7]L.Wang,L.Wang,J.Zhang,H.Wang,F.-S.Xiao,Chin.J.Catal.,2018,39,1608-1614.
[8]A.Trovarelli,Catal.Rev.Sci.Eng.,1996,38,439-520.
[9]J.Ka?par,P.Fornasiero,M.Graziani,Catal.Today,1999,50,285-298.
[10]J.Li,G.Lu,G.Wu,D.Mao,Y.Wang,Y.Guo,Catal.Sci.Technol.,2012,2,1865-1871.
[11]H.Wang,H.Zhu,Z.Qin,F.Liang,G.Wang,J.Wang,J.Catal.,2009,264,154-162.
[12]F.Grillo,M.M.Natile,A.Glisenti,Appl.Catal.B,2004,48,267-274.
[13]L.Lukashuk,K.F?ttinger,E.Kolar,C.Rameshan,D.Teschner,M.H?vecker,A.Knop-Gericke,N.Yigit,H.Li,E.Mc Dermott,M.St?ger-Pollach,G.Rupprechter,J.Catal.,2016,344,1-15.
[14]H.Oh.K.I.Hee,N.S.Lee,Y.D.Kim,M.H.Kim,Mater.Res.Express.,2017,4,085041/1-085041/9.
[15]S.Deng,N.Chen,D.Deng,Y.Li,X.Xing,Y.Wang,Ceram.Int.,2015,41,11004-11012.
[16]A.Jha,D.W.Jeong,Y.L.Lee,I.W.Nah,H.S.Roh,RSC Adv.,2015,5,103023-103029.
[17]M.P.Woods,P.Gawade,B.Tan,U.S.Ozkan,Appl.Catal.B,2010,97,28-35.
[18]L.An,L.Huang,P.Zhou,J.Yin,H.Liu,P.Xi,Adv.Funct.Mater.,2015,25,6814-6822.
[19]R.Ba,Y.Zhao,L.Yu,J.Song,S.Huang,L.Zhong,Y.Sun,Y.Zhu,Nanoscale,2015,7,12365-12371.
[20]A.Serov,N.I.Andersen,A.J.Roy,I.Matanovic,K.Artyushkova,P.Atanassov,J.Electrochem.Soc.,2015,162,F449-F454.
[21]L.Xue,C.Zhang,H.He,Y.Teraoka,Appl.Catal.B,2007,75,167-174.
[22]J.Jansson,M.Skoglundh,E.Fridell,P.Thorm?hlen,Top.Catal.,2001,16,385-389.
[23]J.Jansson,J.Catal.,2000,194,55-60.
[24]K.Nakamoto,J.Fujita,S.Tanaka,M.Kobayashi,J.Am.Chem.Soc.,1957,79,4904-4908.
[25]A.A.Khassin,T.M.Yurieva,V.V.Kaichev,V.I.Bukhtiyarov,A.A.Budneva,E.A.Paukshtis,V.N.Parmon,J.Mol.Catal.A,2001,175,189-204.
[26]C.Li,Y.Sakata,T.Arai,K.Domen,K.Maruya,T.Onishi,J.Chem.Soc.,Faraday Trans.1.,1989,85,929-943.
[27]M.Chang,H.M.Yun,S.S.Dong,L.Y.Zhang,M.M.Zhen,Y.Y.Jiao,H.W.Yu,Infrar.Technol.,2016,38,803-810.
[28]H.Wijnja,C.P.Schulthess,Spectrochim.Acta A,1999,55,861-872.
[29]J.A.Goldsmith,S.D.Ross,Spectrochim.Acta A,1968,24,993-998.
[30]A.Bielański,J.Haber,Catal.Rev.Sci.Eng.,1979,19,1-41.
[31]J.P.Jolivet,Y.P.Thomas,B.Taravel,V.Lorenzelli,G.Busca,J.Mol.Struct.,1982,79,403-408.
[2]X.Xie,Y.Li,Z.Q.Liu,M.Haruta,W.Shen,Nature,2009,458,746-749.
[3]M.J.Pollard,B.A.Weinstock,T.E.Bitterwolf,P.R.Griffiths,A.P.Newbery,J.B.Paine III,J.Catal.,2008,254,218-225.
[4]J.Jansson,A.E.C.Palmqvist,E.Fridell,M.Skoglundh,L.?sterlund,P.Thorm?hlen,V.Langer,J.Catal.,2002,211,387-397.
[5]L.F.Liotta,G.Di Carlo,G.Pantaleo,G.Deganello,Catal.Commun.,2005,6,329-336.
[6]A.Trovarelli,C.de Leitenburg,M.Boaro,G.Dolcetti,Catal.Today.,1999,50,353-367.
[7]L.Wang,L.Wang,J.Zhang,H.Wang,F.-S.Xiao,Chin.J.Catal.,2018,39,1608-1614.
[8]A.Trovarelli,Catal.Rev.Sci.Eng.,1996,38,439-520.
[9]J.Ka?par,P.Fornasiero,M.Graziani,Catal.Today,1999,50,285-298.
[10]J.Li,G.Lu,G.Wu,D.Mao,Y.Wang,Y.Guo,Catal.Sci.Technol.,2012,2,1865-1871.
[11]H.Wang,H.Zhu,Z.Qin,F.Liang,G.Wang,J.Wang,J.Catal.,2009,264,154-162.
[12]F.Grillo,M.M.Natile,A.Glisenti,Appl.Catal.B,2004,48,267-274.
[13]L.Lukashuk,K.F?ttinger,E.Kolar,C.Rameshan,D.Teschner,M.H?vecker,A.Knop-Gericke,N.Yigit,H.Li,E.Mc Dermott,M.St?ger-Pollach,G.Rupprechter,J.Catal.,2016,344,1-15.
[14]H.Oh.K.I.Hee,N.S.Lee,Y.D.Kim,M.H.Kim,Mater.Res.Express.,2017,4,085041/1-085041/9.
[15]S.Deng,N.Chen,D.Deng,Y.Li,X.Xing,Y.Wang,Ceram.Int.,2015,41,11004-11012.
[16]A.Jha,D.W.Jeong,Y.L.Lee,I.W.Nah,H.S.Roh,RSC Adv.,2015,5,103023-103029.
[17]M.P.Woods,P.Gawade,B.Tan,U.S.Ozkan,Appl.Catal.B,2010,97,28-35.
[18]L.An,L.Huang,P.Zhou,J.Yin,H.Liu,P.Xi,Adv.Funct.Mater.,2015,25,6814-6822.
[19]R.Ba,Y.Zhao,L.Yu,J.Song,S.Huang,L.Zhong,Y.Sun,Y.Zhu,Nanoscale,2015,7,12365-12371.
[20]A.Serov,N.I.Andersen,A.J.Roy,I.Matanovic,K.Artyushkova,P.Atanassov,J.Electrochem.Soc.,2015,162,F449-F454.
[21]L.Xue,C.Zhang,H.He,Y.Teraoka,Appl.Catal.B,2007,75,167-174.
[22]J.Jansson,M.Skoglundh,E.Fridell,P.Thorm?hlen,Top.Catal.,2001,16,385-389.
[23]J.Jansson,J.Catal.,2000,194,55-60.
[24]K.Nakamoto,J.Fujita,S.Tanaka,M.Kobayashi,J.Am.Chem.Soc.,1957,79,4904-4908.
[25]A.A.Khassin,T.M.Yurieva,V.V.Kaichev,V.I.Bukhtiyarov,A.A.Budneva,E.A.Paukshtis,V.N.Parmon,J.Mol.Catal.A,2001,175,189-204.
[26]C.Li,Y.Sakata,T.Arai,K.Domen,K.Maruya,T.Onishi,J.Chem.Soc.,Faraday Trans.1.,1989,85,929-943.
[27]M.Chang,H.M.Yun,S.S.Dong,L.Y.Zhang,M.M.Zhen,Y.Y.Jiao,H.W.Yu,Infrar.Technol.,2016,38,803-810.
[28]H.Wijnja,C.P.Schulthess,Spectrochim.Acta A,1999,55,861-872.
[29]J.A.Goldsmith,S.D.Ross,Spectrochim.Acta A,1968,24,993-998.
[30]A.Bielański,J.Haber,Catal.Rev.Sci.Eng.,1979,19,1-41.
[31]J.P.Jolivet,Y.P.Thomas,B.Taravel,V.Lorenzelli,G.Busca,J.Mol.Struct.,1982,79,403-408.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |