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多孔碳材料的研究进展多孔碳材料简介多孔碳材料合成多孔碳材料应用前景展望2多孔碳材料3 常见的多孔碳材料有:活性碳、活性碳纤维、介孔碳、碳纳米管、碳分子筛等。比表面积比表面积大大质量轻质量轻导电导热导电导热化学稳定性高化学稳定性高4多孔碳材料多孔碳材料吸附分离材吸附分离材料料储能材料储能材料电极材料电极材料多孔材料多孔材料多孔碳材料合成方法合成方法合成方法活化法活化法化学活化法化学活化法物理活化法物理活化法模板法模板法硬模板法硬模板法软模板法软模板法5活化法6物理活化法:采用水蒸气、水蒸气、CO2、空气、空气等气体作为活化剂,在高温下与碳化料接触进行活化。物理活物理活化法化法把化学药品加入原料中,然后在惰性气体介质中加热活化的方法。常用活化剂有:KOH,H3PO4,ZnCl2等等,它们都起到了脱水剂和氧化剂的作用。化学活化学活化法化法硬模板法 硬模板法流程:先合成多孔分子筛,以其为硬模板,将碳前驱体灌入其孔道中,将形成的纳米有机物/硅复合材料经过高温碳化和模板刻蚀技术,最终获得多孔碳材料。其孔结构和孔道尺寸主要取决于所使用的硬模板的结构,通过选择不同结构的硬模板,来控制和合成反相复制模板的多孔碳材料。7硬模板法 1999年,韩国科学家Ryoo等人以蔗糖为碳源,以介孔二氧化硅分子筛MCM-48为模板,首次合成出有序介孔碳材料CMK-1。8Ryoo R,Sang H J,Jun S.ChemInform Abstract:Synthesis of Highly Ordered Carbon Molecular Sieves via Template-Mediated Structural Transformation.J.Cheminform,1999,30(50).Lee J,Kim J,Hyeon T.Recent progress in the synthesis of porous carbon materialsJ.Advanced Materials,2011,18(18):2073-2094.硬模板法9Ryoo以介孔氧化硅SBA-15为模板,合成了介孔碳CMK-3和CMK-5。当碳源全部填充SBA-15 的孔道时,得到纳米棒状CMK-3;如果碳源部分填充或仅在孔道的内表面包覆一层,得到的是一空心的纳米管型的CMK-5。CMK-3CMK-5Ryoo R,Sang H J,Jun S.ChemInform Abstract:Synthesis of Highly Ordered Carbon Molecular Sieves via Template-Mediated Structural Transformation.J.Cheminform,1999,30(50).Joo S H,Choi S J,Oh I,et al.Ordered nanoporous arrays of carbon supporting high dispersions of platinum nanoparticlesJ.Nature,2001,412(6843):169-72.硬模板法10软模板法 软模板法利用表面活性剂作为模板剂,通过表面活性剂和碳源之间的相互作用,经过自组装形成多孔结构。11赵东元课题组以酚醛树脂为碳源,在乙醇做溶剂条件下,利用溶剂挥发诱导自组装将嵌段共聚物与碳源自组装形成具有介孔结构的高分子聚合物,而后经过脱除模板和预碳化得到有序介孔碳材料。Wan Y,Shi Y,Zhao D.Supramolecular Aggregates as Templates:Ordered Mesoporous Polymers and CarbonsJ.Chemistry of Materials,2007,20(3):932-945.软模板法 Dai Sheng小组将PS-P4VP型嵌段共聚物与间苯二酚甲醛树脂组装得到嵌段共聚物-酚醛树脂复合材料,在甲醛蒸气处理和热固后碳化,得到了高度有序的介孔碳材料。12Chengdu L,Kunlun H,Guiochon G A,et al.Synthesis of a large-scale highly ordered porous carbon film by self-assembly of block copolymers.J.Angewandte Chemie International Edition,2004,43(43):57855789.储氢 多孔碳材料具有密度小、比表面积大等结构特征,而被用于制备储氢材料。美国国立可再生能源实验室,采用TPD(程序控温脱附仪)测量单壁纳米碳管(SWNT)的载氢量,从实验结果推测在常温下SWNT能储存5%10%wt的氢气,并认为SWNT接近氢燃料电池汽车的应用标准9%wt。Chen等对金属掺杂对纳米碳管储氢容量的影响进行了研究,他们称掺杂Li 及掺杂K的多壁碳纳米管在常压,200-400条件下的储氢量分别高达20%及14%。13Dillon A C,Jones K M,Bekkedahl T A,et al.Storage of hydrogen in single-walled carbon nanotubesJ.Nature,1997,386(6623):377-379.Chen P,Wu X,Lin J,et al.High H2 uptake by alkali-doped carbon nanotubes under ambient pressure and moderate temperaturesJ.Science,1999,285(5424):91-3.储氢 Jin研究了不同比表面积(900-2800m2/g)和孔容(0.43-2.17cm2/g)的活性碳的储氢效果,结果发现比表面积和孔容都和吸氢量呈线性关系。14Jin H,Lee Y S,Hong I.Hydrogen adsorption characteristics of activated carbonJ.Catalysis Today,2007,120(120):399-406.储氢 Cogotsi等使用不同碳化物前驱体,氯化处理和调节活化温度合成特定孔径的多孔碳,发现在同样的比表面积下,小于或等于1nm的小孔储氢效率更高。15Yury G,Dash R K,Gleb Y,et al.Tailoring of nanoscale porosity in carbide-derived carbons for hydrogen storage.J.Journal of the American Chemical Society,2005,127(46):16006-7.超级电容器 碳材料,如碳粉末、碳纤维、碳凝胶、碳纳米管、碳复合物、碳垫、碳独块巨石、碳箔等,被广泛的应用于超级电容器。16北京科技大学范丽珍教授用氨基葡萄糖为原料合成氮掺杂碳材料,比容量在 H2SO4和 KOH 溶液中分别可达 300 和 220F/g。Li Z,Li-Zhen F,Meng-Qi Z,et al.Nitrogen-containing hydrothermal carbons with superior performance in supercapacitors.J.Advanced Materials,2010,22(45):52025206.17南京大学胡征教授以 MgO 为模板、苯蒸汽为碳源合成了石墨质的碳纳米笼,在 KOH 溶液中 比电容值最高可达 260F/g。超级电容器Xie K,Qin X,Wang X,et al.Carbon Nanocages as Supercapacitor Electrode MaterialsJ.Advanced Materials,2012,24(3):347-52.吸附分离 多孔碳材料中掺杂 N 原子或含氮碱性基团后,可以极大地调变多孔碳材料的表面积、孔道结构、表面化学特性,因此被许多研究者用于气体的吸附研究。Li等用氨水改性在活性碳纤维表面引入含氮基团。发现,与具有相近表面积的商业活性碳纤维相比,含氮活性碳纤维对SO2的脱除具有更好的性能。这是由于经过氨水处理后的氮碳纤维表面含有丰富的含氮基团,能够增强对SO2的吸附能力。18Li K,Ling L,Lu C,et al.Catalytic removal of SO2 over ammonia-activated carbon fibersJ.Carbon,2001,39(39):1803-1808.Vimlesh C,Seong Uk Y,Seon Ho K,et al.Highly selective CO2 capture on N-doped carbon produced by chemical activation of polypyrrole functionalized graphene sheets.J.Chemical Communications,2012,48(5):735-7.CO2吸附 Su等人通过商业的酚醛树脂,与1 wt%碳纳米管混合,经过煅烧和CO2气体物理活化之后得到了大孔-微孔这样的分级孔结构。特别地,该材料在低CO2浓度的情况下(25和0.15atm)CO2的吸附量仍能达到1.18mmol/g。19Jin Y,Hawkins S C,Chi P H,et al.Carbon nanotube modified carbon composite monoliths as superior adsorbents for carbon dioxide captureJ.Energy&Environmental Science,2013,6(9):2591-2596.CO2吸附分离20 Lu等人利用苯并恶嗪-酚醛树脂聚合物为碳源和氮源,经过煅烧得到了氮掺杂的块体碳材料。这类碳材料可以承受15.6MPa的压力,在压力1bar和0的条件下,CO2的吸附量范围是是3.3-4.9 mmol/g。在CO2/N2的混合气体中,CO2的选择性系数从13到28。Guang-Ping H,Wen-Cui L,Dan Q,et al.Structurally designed synthesis of mechanically stable poly(benzoxazine-co-resol)-based porous carbon monoliths and their application as high-performance CO2 capture sorbents.J.Journal of the American Chemical Society,2011,133(29):11378-11388.碳分子筛空分材料 氧氮两种气体分子在分子筛表面上的扩散速率不同,直径较小的氧气分子扩散速率较快,较多的进入碳分子筛微孔,直径较大的氮气分子扩散速率较慢,进入碳分子筛微孔较少。根据氮氧通过CMS 的速率不同,达到分离目的。目前,空分制氮技术已经很成熟,已经可以制得纯度为99%99.9%的氮气。21功能性改进22活性炭纤维用硫酸处理后可催化NO与NH3 反应生成N2,提高低浓度NO的脱除率。添加溴的多孔炭可作为强催化剂氧化甲硫醚、二硫甲烷。催化活性炭纤维上分散MgO粒子可大大增加对甲烷的吸附。在多孔碳表面添加氯化亚铜,可提高对CO的吸附。吸附多孔碳上添加有杀菌作用的银粒子后对大肠杆菌、黄色葡萄状球菌等都有极好的杀菌作。杀菌前景展望前景展望 多孔碳材料原料来源丰富,合成方法多样,可以采用不同的有机分子作为前驱物,通过针对性地设计反应路线,表面改性、负载高活性金属纳米颗粒以及构筑复合型碳材料等手段得到符合不同要求的碳材料。23参考文献Ryoo R,Sang H J,Jun S.ChemInform Abstract:Synthesis of Highly Ordered Carbon Molecular Sieves via Template-Mediated Structural Transformation.J.Cheminform,1999,30(50).Ryoo R,Sang H J,Jun S.ChemInform Abstract:Synthesis of Highly Ordered Carbon Molecular Sieves via Template-Mediated Structural Transformation.J.Cheminform,1999,30(50).Joo S H,Choi S J,Oh I,et al.Ordered nanoporous arrays of carbon supporting high dispersions of platinum nanoparticlesJ.Nature,2001,412(6843):169-72.Wan Y,Shi Y,Zhao D.Supramolecular Aggregates as Templates:Ordered Mesoporous Polymers and Carbons J.Chemistry of Materials,2007,20(3):932-945.Dillon A C,Jones K M,Bekkedahl T A,et al.Storage of hydrogen in single-walled carbon nanotubesJ.Nature,1997,386(6623):377-379.Chen P,Wu X,Lin J,et al.High H2 uptake by alkali-doped carbon nanotubes under ambient pressure and moderate temperaturesJ.Science,1999,285(5424):91-3.Jin H,Lee Y S,Hong I.Hydrogen adsorption characteristics of activated carbonJ.Catalysis Today,2007,120(120):399-406.Yury G,Dash R K,Gleb Y,et al.Tailoring of nanoscale porosity in carbide-derived carbons for hydrogen storage.J.Journal of the American Chemical Society,2005,127(46):16006-7.Li Z,Li-Zhen F,Meng-Qi Z,et al.Nitrogen-containing hydrothermal carbons with superior performance in supercapacitors.J.Advanced Materials,2010,22(45):52025206.Xie K,Qin X,Wang X,et al.Carbon Nanocages as Supercapacitor Electrode MaterialsJ.Advanced Materials,2012,24(3):347-52.Vimlesh C,Seong Uk Y,Seon Ho K,et al.Highly selective CO2 capture on N-doped carbon produced by chemical activation of polypyrrole functionalized graphene sheets.J.Chemical Communications,2012,48(5):735-7.Jin Y,Hawkins S C,Chi P H,et al.Carbon nanotube modified carbon composite monoliths as superior adsorbents for carbon dioxide captureJ.Energy&Environmental Science,2013,6(9):2591-2596.Guang-Ping H,Wen-Cui L,Dan Q,et al.Structurally designed synthesis of mechanically stable poly(benzoxazine-co-resol)-based porous carbon monoliths and their application as high-performance CO2 capture sorbents.J.Journal of the American Chemical Society,2011,133(29):11378-11388.24感谢您的聆听!
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