磁性碳纳米管负载铑催化剂在丁腈橡胶氢化方面的应用研究
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摘要
采用水热合成法,在多壁碳纳米管(MWCNTs)表面原位生成四氧化三铁(Fe_3O_4)纳米粒子,制备碳纳米管磁性载体(MWCNTs@Fe_3O_4),再将铑(Rh)纳米粒子负载在该磁性载体上,形成新型磁性碳纳米管催化剂(MWCNTs@Fe_3O_4@Rh)。采用透射电子显微镜(TEM),X-射线粉末衍射(XRD),X射线光电子能谱(XPS)等手段表征催化剂的结构和形貌,从TEM可以看出碳纳米管缠绕在直径300nm～400nm的四氧化三铁(Fe_3O_4)纳米粒子上,并且表面负载有直径小于10nm的Rh纳米粒子。采用XRD和XPS等手段也证明Fe_3O_4以及Rh粒子的存在。同时对该催化剂在丁腈橡胶(NBR)选择性加氢方面进行探索。在120℃,4.0MPa,8h条件下,得到了氢化率达到98.17%的氢化丁腈橡胶(HNBR),该催化剂对CC双键具有良好的选择性。将制备的MWCNTs@Fe_3O_4@Rh催化剂与传统的MWCNTs负载Rh的催化剂(MWCNTs@Rh)进行循环使用,发现在重复3次之后,新型催化剂仍能达到91.53%以上的氢化度,而传统的催化剂不到40%。
Fe_3O_4 particles were combined with multi-walled carbon nanotubes(MWCNTs)to form MWCNTs@Fe_3O_4 magnetic carrier by in-situ method.Rhodium nanoparticles were loaded onto surface of magnetic carbon nanotubes to form MWCNTs@Fe_3O_4@Rh magnetic carbon nanotube catalysts.The structure and morphology of the catalyst were characterized by TEM,XRD and XPS.It can be seen from TEM that the carbon nanotubes were entangled in Fe_3O_4 nanoparticles with diameter of 300～400 nm,and the surface loaded Rh nanoparticles with diameter less than10 nm.The Rh nanoparticles and Fe_3O_4 nanoparticles had a better load on the surface of the carbon nanotube.The existence of Fe_3O_4 and Rh particles can be demonstrated by powder X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).The hydrogenation of nitrile butadiene rubber(NBR)was used to evaluate the catalytic properties of MWCNTs@Fe_3O_4@Rh.The conversion of 98.17% and good selectivitytor C C were obtained under optimum condition(120℃,4.0 MPa,8 h).In addition,the traditional catalyst loaded on carbon nanotubes directly(MWCNT@Rh)and prepared MWCNTs@Fe_3O_4@Rh catalyst were both recycled.After repeating 3 times,the hydrogenation degree of catalysts prepared still remain was 91.53%,while the hydrogenation degree of original catalyst was less than 40%.
Fe_3O_4 particles were combined with multi-walled carbon nanotubes(MWCNTs)to form MWCNTs@Fe_3O_4 magnetic carrier by in-situ method.Rhodium nanoparticles were loaded onto surface of magnetic carbon nanotubes to form MWCNTs@Fe_3O_4@Rh magnetic carbon nanotube catalysts.The structure and morphology of the catalyst were characterized by TEM,XRD and XPS.It can be seen from TEM that the carbon nanotubes were entangled in Fe_3O_4 nanoparticles with diameter of 300～400 nm,and the surface loaded Rh nanoparticles with diameter less than10 nm.The Rh nanoparticles and Fe_3O_4 nanoparticles had a better load on the surface of the carbon nanotube.The existence of Fe_3O_4 and Rh particles can be demonstrated by powder X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).The hydrogenation of nitrile butadiene rubber(NBR)was used to evaluate the catalytic properties of MWCNTs@Fe_3O_4@Rh.The conversion of 98.17% and good selectivitytor C C were obtained under optimum condition(120℃,4.0 MPa,8 h).In addition,the traditional catalyst loaded on carbon nanotubes directly(MWCNT@Rh)and prepared MWCNTs@Fe_3O_4@Rh catalyst were both recycled.After repeating 3 times,the hydrogenation degree of catalysts prepared still remain was 91.53%,while the hydrogenation degree of original catalyst was less than 40%.
引文
[1] Han K Y,Zuo H R,Zhu Z W,et al.High performance of palladium nanoparticles supported on carbon nanotubes for the hydrogenation of commercial polystyrene[J].Industrial &Engineering Chemistry Research,2013,52(50):17750-17759.
[2] Maheshwari S,Michael Tsapatsis A,Bates F S.Synthesis and thermodynamic properties of poly(cyclohexylethylene-b-dimethylsiloxane-b-cyclohexylethylene)[J].Macromolecules,2007,40(18):6638-6646.
[3] 周淑芹,姚明,徐瑞清,等.铑钌双金属双配体催化剂制备氢化丁腈橡胶[J].北京化工大学学报(自然科学版),2002,29(4):17-19.
[4] 周淑芹,姚明,岳冬梅,等.一种新型催化剂制备氢化丁腈橡胶的研究[J].高分子材料科学与工程,2002,18(5):69-72.
[5] 许贵显,周淑芹,岳冬梅,等.加氢催化剂,其制法及在不饱和共聚物加氢中的应用:中国,CN1263111[P].2000-08-16.
[6] Wei Z,Wu J,Pan Q,et al.Direct catalytic hydrogenation of an acrylonitrile-butadiene rubber latex using wilkinson's catalyst[J].Macromolecular Rapid Communications,2010,26(23):1768-1772.
[7] Yin L,Wei Z,Pan Q,et al.Hydrogenation of acrylonitrile-butadiene rubber latex using in situ synthesized RhCl(PPh3)3,catalyst[J].Applied Catalysis A General,2013,457(16):62-68.
[8] Yang L,Pan Q,Rempel G L.Development of a green separation technique for recovery of wilkinson's catalysts from bulk hydrogenated nitrile butadiene rubber[J].Catalysis Today,2013,207(207):153-161.
[9] Liu Y,Kim H,Pan Q,et al.Hydrogenation of acrylonitrile-butadiene copolymer latex using water-soluble rhodium catalysts[J].Catalysis Science &Technology,2013,3(10):2689-2698.
[10] Yang L,Wang H,Rempel G L,et al.Recovery of wilkinson's catalyst from hydrogenated nitrile butadiene rubber latex nanoparticles[J].Topics in Catalysis,2014,57(17/20):1558-1563.
[11] Piya-Areetham P,Prasassarakich P,Rempel G L.Organic solvent-free hydrogenation of natural rubber latex and synthetic polyisoprene emulsion catalyzed by water-soluble rhodium complexes[J].Journal of Molecular Catalysis A Chemical,2013,372(3):151-159.
[12] Horikoshi R,Kobayashi Y,Kageyama H.Illustrating catalysis with interlocking building blocks:a ruthenium carbene complex for olefin metathesis reactions[J].J Chem Educ,2014,91(2):255-258.
[13] Yamashita T,Hayes P.Analysis of XPS spectra of Fe2+,and Fe3+,ions in oxide materials[J].Applied Surface Science,2008,254(8):2441-2449.
[14] Cao P,Ni Y,Zou R,et al.Enhanced catalytic properties of rhodium nanoparticles deposited on chemically modified SiO2for hydrogenation of nitrile butadiene rubber[J].Rsc Advances,2014,5(5):3417-3424.
[2] Maheshwari S,Michael Tsapatsis A,Bates F S.Synthesis and thermodynamic properties of poly(cyclohexylethylene-b-dimethylsiloxane-b-cyclohexylethylene)[J].Macromolecules,2007,40(18):6638-6646.
[3] 周淑芹,姚明,徐瑞清,等.铑钌双金属双配体催化剂制备氢化丁腈橡胶[J].北京化工大学学报(自然科学版),2002,29(4):17-19.
[4] 周淑芹,姚明,岳冬梅,等.一种新型催化剂制备氢化丁腈橡胶的研究[J].高分子材料科学与工程,2002,18(5):69-72.
[5] 许贵显,周淑芹,岳冬梅,等.加氢催化剂,其制法及在不饱和共聚物加氢中的应用:中国,CN1263111[P].2000-08-16.
[6] Wei Z,Wu J,Pan Q,et al.Direct catalytic hydrogenation of an acrylonitrile-butadiene rubber latex using wilkinson's catalyst[J].Macromolecular Rapid Communications,2010,26(23):1768-1772.
[7] Yin L,Wei Z,Pan Q,et al.Hydrogenation of acrylonitrile-butadiene rubber latex using in situ synthesized RhCl(PPh3)3,catalyst[J].Applied Catalysis A General,2013,457(16):62-68.
[8] Yang L,Pan Q,Rempel G L.Development of a green separation technique for recovery of wilkinson's catalysts from bulk hydrogenated nitrile butadiene rubber[J].Catalysis Today,2013,207(207):153-161.
[9] Liu Y,Kim H,Pan Q,et al.Hydrogenation of acrylonitrile-butadiene copolymer latex using water-soluble rhodium catalysts[J].Catalysis Science &Technology,2013,3(10):2689-2698.
[10] Yang L,Wang H,Rempel G L,et al.Recovery of wilkinson's catalyst from hydrogenated nitrile butadiene rubber latex nanoparticles[J].Topics in Catalysis,2014,57(17/20):1558-1563.
[11] Piya-Areetham P,Prasassarakich P,Rempel G L.Organic solvent-free hydrogenation of natural rubber latex and synthetic polyisoprene emulsion catalyzed by water-soluble rhodium complexes[J].Journal of Molecular Catalysis A Chemical,2013,372(3):151-159.
[12] Horikoshi R,Kobayashi Y,Kageyama H.Illustrating catalysis with interlocking building blocks:a ruthenium carbene complex for olefin metathesis reactions[J].J Chem Educ,2014,91(2):255-258.
[13] Yamashita T,Hayes P.Analysis of XPS spectra of Fe2+,and Fe3+,ions in oxide materials[J].Applied Surface Science,2008,254(8):2441-2449.
[14] Cao P,Ni Y,Zou R,et al.Enhanced catalytic properties of rhodium nanoparticles deposited on chemically modified SiO2for hydrogenation of nitrile butadiene rubber[J].Rsc Advances,2014,5(5):3417-3424.