功能化碳纳米管电解水析氢催化剂

发布时间：2018-04-03 14:27

本文选题：离子液体　切入点：碳纳米管　出处：《西南大学》2017年硕士论文

【摘要】：氢气是一种洁净友好的二次能源,具有来源广泛,产物为水,清洁环保,可以循环使用等优点。电解水制氢是一种高效的制氢方式,电解水制氢的核心技术为阴极析氢催化剂。现有的析氢催化剂有Pt等贵金属催化剂,Ni、Co等非贵金属催化剂,过渡金属磷化物催化剂,C60(OH)8和C3N4非金属催化剂等。贵金属Pt具有良好的电催化性能,但是它在地球上储量有限,价格昂贵,限制了其大规模使用的可能性。Ni和Co等非贵金属催化剂的催化性能相比较于贵金属有一定差距,在酸性条件下它会被腐蚀和钝化。过渡金属磷化物催化剂具有良好的电催化性能,如MoP,WP,CoP。但以往合成磷化物电催化剂的过程中,合成工艺复杂,并伴有有机废物的产生。近期的研究中,非金属C60(OH)8和C3N4被研制出来,这类催化剂显示出良好的电催化活性。但是这类电催化剂的合成路径复杂,且合成费用昂贵。因此,现在急需研究制备出性能良好的电解水析氢催化剂。基于以上研究背景,本论文主要进行了以下三方面的研究:制备1-氨丙基-3-甲基咪唑溴盐功能化碳纳米管复合物(AMIM-Br-CNTs)、磷化铁-碳纳米管复合物(FeP-CNTs)和乙二胺-碳纳米管复合物(EDA-CNTs)。在本论文的研究中,主要采用FT-IR、XPS、XRD和TGA等物性评价方法对所制得的析氢电催化剂进行表征。其在酸性条件下的析氢电化学行为进行系统的评价,并揭示其具体析氢机理,本论文的创新工作具体如下:(1)本论文制备出离子液体1-氨丙基-3-甲基咪唑溴盐,并对多壁碳纳米管进行酸化处理。在脱水剂DCC的作用下,将离子液体连接在多壁碳纳米管上,制备出1-氨丙基-3-甲基咪唑-溴盐碳纳米管复合物(AMIM-Br-MWCNTs),电化学测试结果显示,该催化剂的电化学析氢起峰电位是-350 mV,Tafel斜率为125.62 mV/dec。经过XPS和FT-IR研究发现,1-氨丙基-3-甲基咪唑溴盐在与酸化碳纳米管连接以后形成的酰胺基团拥有较强的质子吸附能力,多壁碳纳米管能够传递电子,促进质子的还原,使得催化剂拥有较好的电催化能力。(2)本论文制备出离子液体N,N-4-甲酯基-苯基-N-甲基葡萄糖溴盐(MBMG-Br),再将其与三氯化铁混合来制备含铁的离子液体(MBMG-FeCl3Br)。将离子液体(MBMG-FeCl3Br)与碳纳米管进行均匀混合,最后放置在磁舟里面,用次磷酸钠进行磷化,制备出磷化铁-碳纳米管(FeP-CNTs)。电化学测试结果显示,该催化剂的起峰电位是-70 m V,Tafel斜率为75.9 mV/dec。(3)本论文制备出酸化碳纳米管,使用DCC作为脱水剂,将乙二胺连接到酸化碳纳米管上,制备出乙二胺-碳纳米管(EDA-CNTs)。电化学测试结果显示,该催化剂的电化学析氢起峰电位是-150 mV,Tafel斜率为116 mV/dec。经过XPS和FT-IR研究发现,乙二胺与酸化碳纳米管连接后形成的酰胺基团拥有较强的质子吸附能力,多壁碳纳米管能够传递电子,促进质子的还原,使得电催化剂拥有较好的电催化能力。
[Abstract]:Hydrogen is a kind of clean and friendly secondary energy, with the advantages of wide source, water, clean and environmental protection, recycling and so on.Electrolytic water hydrogen production is an efficient way of hydrogen production. The core technology of electrolytic water hydrogen production is cathodic hydrogen evolution catalyst.The existing catalysts for hydrogen evolution include Pt and other noble metal catalysts, such as non-noble metal catalysts, such as transition metal phosphates, such as C60OHH8 and C3N4 nonmetallic catalysts.The noble metal Pt has good electrocatalytic performance, but it has limited storage on the earth and high price, which limits the possibility of large-scale use of non-noble metal catalysts, such as Ni and Co, which have a certain gap compared with the noble metals.It will be corroded and passivated under acidic conditions.Transition metal phosphide catalysts have good electrocatalytic properties, such as MoPX WPX CoP.However, in the past, the synthesis process of phosphate electrocatalyst was complicated and accompanied by organic waste.In recent studies, nonmetallic C60(OH)8 and C3N4 have been developed, and these catalysts show good electrocatalytic activity.However, the synthesis path of this kind of electrocatalyst is complex and expensive.Therefore, it is urgent to study and prepare electrolysis hydrogen evolution catalyst with good performance.Based on the above research background, the following three aspects were studied: preparation of 1-aminopropyl-3-methyl imidazolium bromide functionalized carbon nanotube complexes (AmmiM-Br-CNTsN), ferric phosphate-carbon nanotube complexes (FeP-CNTs) and ethylenediamine-carbon nanotube complexes (EDA-CNTs).In this paper, the characterization of the prepared electrocatalysts for hydrogen evolution was carried out by means of the physical property evaluation methods, such as FT-IRN XPSO XRD and TGA.The electrochemical behavior of hydrogen evolution under acidic conditions was systematically evaluated, and the specific mechanism of hydrogen evolution was revealed. The innovative work of this paper was as follows: 1) in this paper, ionic liquid 1-aminopropyl-3-methyl imidazole bromine salt was prepared.The multiwalled carbon nanotubes were acidified.Under the action of dehydrating agent DCC, 1-aminopropyl-3-methyl imidazole-bromine carbon nanotube complex was prepared by linking ionic liquid onto multi-walled carbon nanotubes. The electrochemical test results showed that the ammiM-Br-MWCNTsC nanotube complex was composed of 1-aminopropyl-3-methyl imidazole-bromine salt carbon nanotubes (BCNTs).The electrochemical hydrogen evolution peak potential of the catalyst is -350 MV / Tafel slope of 125.62 MV / r.Through XPS and FT-IR studies, it was found that the amide-group formed by the alkyl 1-aminopropyl-3-methyl imidazolium bromide has strong proton adsorption ability, and multi-walled carbon nanotubes can transfer electrons and promote proton reduction.In this paper, the ionic liquid N-4-methyl-phenyl-N-methyl-phenyl-N-methylglucosyl bromide (MBMG-Brn) was prepared and mixed with ferric chloride to prepare the iron-containing ionic liquid MBMG-FeCl _ 3Br-O _ 3.The ionic liquid MBMG-FeCl3Brand carbon nanotubes (CNTs) were homogeneously mixed. Finally, they were placed in a magnetic boat and phosphated with sodium hypophosphite to prepare FeP-CNTsPhosphate nanotubes.The results of electrochemical measurement showed that the peak potential of the catalyst was -70 MV / Tafel slope of 75.9 MV / dec.3.) in this paper, acidified carbon nanotubes were prepared by using DCC as dehydrating agent, and ethylenediamine was connected to the acid carbon nanotubes to prepare EDA-CNTssof ethylenediamine.Electrochemical measurements showed that the peak potential of electrochemical hydrogen evolution of the catalyst was -150 MV / Tafel slope of 116 MV / r.The results of XPS and FT-IR showed that the amide-group formed by the bonding of ethylenediamine with the acidified carbon nanotubes had strong proton adsorption ability, and the multi-walled carbon nanotubes could transfer electrons and promote the proton reduction.The electrocatalyst has better electrocatalytic ability.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TQ116.2

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