以多聚甲醛为还原剂用液相还原法制备碳载铂催化剂

以多聚甲醛为还原剂用液相还原法制备了直接甲醇燃料电池（DMFC）用的碳载Pt（Pt/C）催化剂.结果表明,由于制得的催化剂中Pt晶粒的平均粒径小,结晶度低,因此对甲醇氧化的电催化性能优于商品化的E-TEK公司的Pt/C（Pt/C-E）催化剂和以甲醇为还原剂制得的P/C（Pt/C-M）催化剂.     

活性炭负载Ptm^Au催化剂的制备与甲醇电催化氧化反应活性

采用溶胶负载法制备了Ptm^Au/C催化剂（m代表Pt/Au原子比）,通过X射线衍射、紫外-可见吸收光谱及透射电镜对催化剂进行了表征.利用循环伏安法测定了催化剂对甲醇电催化氧化反应的活性.考查了Pt/Au原子比和活性炭载体的预处理方式对甲醇电催化氧化反应活性的影响.结果表明,Pt0.05^Au/C对甲醇氧化的催化性能明显强于Pt/C催化剂;Pt/Au原子比越小,其催化活性相对越高;与未处理的活性炭相比,经过HNO3和HCl处理的活性炭负载Pt0.05^Au后,其电催化活性有所降低.     

中微孔活性炭负载铂催化剂制备及其催化降解乙醇性能

分别以具有中微孔、微孔和中孔的颗粒活性炭为载体,制备Pt负载的铂炭催化剂.使用BET、SEM、XPS、TEM等对所制备的材料进行物性结构表征;使用固定床反应器表征铂炭催化剂对乙醇的热催化降解性能.研究表明,Pt负载量为0.05％(质量分数)、载体具有微孔和中孔混合结构的铂炭催化剂,在280℃时乙醇的降解率为87.81％...     

焙烧温度对Pt/Al_2O_3催化剂催化纤维素转化性能的影响

以溶剂挥发诱导自组装方法合成的有序介孔氧化铝(MA)为载体负载铂,制备了Pt/MA催化剂。考察了载体和催化剂焙烧温度对Pt/MA催化剂催化纤维素转化性能的影响。采用X射线衍射、N2物理吸附、透射电镜和NH3程序升温脱附等手段对载体和催化剂进行了表征,随着载体焙烧温度的升高,氧化铝的有序度、晶相、比表面积、酸量、铂粒径大小均有明显变化。催化结果表明,载体焙烧温度和催化剂焙烧温度对催化剂的催化性能有显著影响。以800℃焙烧的氧化铝为载体负载铂,再经400℃焙烧制得的催化剂活性最高,六元醇的选择性达到了78.5%。     

Pt/C/聚砜型催化剂层的制备及性能研究

利用聚砜代替聚四氟乙烯,用循环伏安法,通过一步反应直接在高温裂解石墨(炭棒)电极上制备了Pt/C/聚砜型催化剂层.该催化剂层对甲醇的氧化呈现很好的电催化活性和稳定性,并系统研究了制备条件以及甲醇酸度、浓度对催化活性的影响.相对其他酸,在硫酸中电沉积所得Pt/C催化剂有更好的催化活性;催化剂的活性随甲醇溶液酸度的增加而增大;峰电流与甲醇浓度成正比.     

Effect of supporting materials on the electrocatalytic activity,stability and selectivity of noble metal-based catalysts for oxygen reduction and hydrogen evolution reactions

Carbonaceous and alternative supporting materials for platinum(Pt) and palladium(Pd) have been explored for the cathodic electrocatalysis in low-temperature fuel cells. Pd and Pt are widely used for catalysis owing to their remarkable electrocatalytic activity toward water splitting and fuel cell reactions. Supporting materials play a paramount role in defining electrocatalytic properties such as durability, selectivity, and activity. The conventional supporting material such as carbon black is unable to fit all the requirements under the severe operating conditions of fuel cells due to its poor corrosion resistance and limited mass transport of fuels to active catalyst sites. Nowadays the scientific research is being concentrated on devising different altered carbonic and carbonfree supporting materials for catalysts to improve the catalytic activity, stability, and selectivity of noble metal electrocatalysts. Lately, Pt, Pd and their alloy catalysts supported on modified carbonaceous and carbon-free materials have attracted solid interest owing to their prominent characteristics contributing to the remarkable fuel cell efficacy. Therefore, it is reasonable to explore this theme, regarding a variety of supporting materials,their advantages, drawbacks and future perspectives. In this mini-review, we selectively summarize recent advancements on several types of key supporting materials: carbon(graphene, carbon nanotubes, mesoporous carbon, and doped carbon nanostructures), non-carbon(transition metals oxides, borides, nitrides, and carbides)and hybrid nanocomposites.     

Ordered nanoporous arrays of carbon supporting high dispersions of platinum nanoparticles.

Nanostructured carbon materials are potentially of great technological interest for the development of electronic, catalytic and hydrogen-storage systems. Here we describe a general strategy for the synthesis of highly ordered, rigid arrays of nanoporous carbon having uniform but tunable diameters (typically 6 nanometres inside and 9 nanometres outside). These structures are formed by using ordered mesoporous silicas as templates, the removal of which leaves a partially ordered graphitic framework. The resulting material supports a high dispersion of platinum nanoparticles, exceeding that of other common microporous carbon materials (such as carbon black, charcoal and activated carbon fibres). The platinum cluster diameter can be controlled to below 3 nanometres, and the high dispersion of these metal clusters gives rise to promising electrocatalytic activity for oxygen reduction, which could prove to be practically relevant for fuel-cell technologies. These nanomaterials can also be prepared in the form of free-standing films by using ordered silica films as the templates.     

预沉淀法制备直接甲醇燃料电池的Pt-Fe/C阴极催化剂

用预沉淀法制备了炭载Pt—Fe（Pt—Fe／C）和炭载Pt（Pt／C）催化剂．发现Pt—Fe／C催化剂对氧还原的电催化活性比Pt／C催化剂高，但对甲醇氧化的电催化活性比Pt／C催化剂差．即使在电解液中有甲醇存在时，Pt—Fe／C催化剂对氧还原的电催化活性仍比Pt／C催化剂高．所以，Pt—Fe／C催化剂适合于用作直接甲醇燃料电池（DMFC）中的阴极催化剂．     

Surface modifications of Pt-based atomically ordered nanoparticles to improve catalytic performances for oxygen reduction reaction

Bimetallic platinum-cobalt (Pt–Co) nanostructure catalysts represent superior catalytic performances for oxygen reduction reaction (ORR). In a variety of Pt–Co catalyst structures, atomically ordered structure catalysts show excellent catalytic performances in the ORR. In this work, for promoting their catalytic performances, atomically ordered PtCo nanoparticles (PtCo/C) with carbon supported were successfully prepared by an improved impregnation method and annealing. Then, the ordered PtCo/C catalysts have been significantly improved by doped with ultralow amount of Au and Cr transition metal. The physical and electrochemical test results demonstrate the Cr–PtCo/C and Au–PtCo/C catalysts have superior catalytic performances including mass activity and stability compared to commercialized Johnson Matthey (JM) Pt/C, which was the result of the modified electronic properties of Pt surface and atomically ordered structure. The presence of Au and Cr enhances the stability of PtCo/C catalysts. This work represents a simple way to promote the catalytic performances of the atomically ordered catalysts.     

制备方法对Pt/CA催化剂电化学性能的影响

以炭气凝胶为载体,分别以甲醛、硼氢化钠和乙二醇为还原剂制备了Pt/CA催化剂。采用XRD技术对催化剂上Pt的分散度和粒径大小进行了分析。结果表明,以乙二醇为还原剂制备的Pt/CA催化剂上Pt分布最均匀,粒径为2.2 nm。通过电化学性能测试,发现3种催化剂的活性大小顺序为Pt/CA-EGPt/CA-HCHOPt/CA-NaBH4,其中催化剂Pt/CA-EG的电化学活性比表面积达到74.1 m2/g,比质量活性达到248.8 A/g,并且其电化学性能远远好于商用催化剂。     

有序中孔铁催化剂的费-托合成催化性能研究

以KIT-6为模板用硬模板法合成了有序中孔铁催化剂,并引入Cu助剂,考察其费-托合成反应催化性能,采用原位小角X-射线衍射和N2物理吸附等对其表征,考察了Cu助剂和CO还原对其催化性能和结构的影响.结果表明：模板法合成的铁催化剂不同于传统沉淀铁催化剂,它具有特殊的有序中孔结构和较大的比表面积,较高的费-托合成反应活性和C5＋选择性.Cu助剂使有序中孔铁催化剂的还原性提高,故活性最高.CO还原后的催化剂为孔径均一的中孔结构,比表面积较大,但有序性降低,存在部分孔坍塌.     

直接甲醇燃料电池PtSn/C催化剂对甲醇氧化的电催化活性

采用低温固相反应法制备了直接甲醇燃料电池用PtSn/C阳极催化剂,采用XRD、TEM等测试方法对催化剂的晶体结构和粒径大小进行了表征. 结果表明:采用低温固相反应法制备的PtSn/C催化剂和Pt/C催化剂均表现为Pt的fcc晶体结构;Sn的加入导致Pt的晶胞参数增大;与同法所制Pt/C催化剂相比较,PtSn/C催化剂中金属Pt在碳载体上分布较均匀,金属粒子的粒径较小,平均粒径约为4.8 nm,从而具有更大的反应表面积. 电化学测试表明,对于甲醇电氧化,PtSn/C催化剂具有比Pt/C催化剂更强的催化能力.     

促进型Pt/C类催化剂对甲醇的电氧化作用

研究了硅钼酸、磷钨酸促进型Pt／C类催化剂对甲醇的电氧化作用．采用循环伏安法和线性伏安法考察了催化剂的制备方法、添加剂、甲醇浓度、反应温度等因素对催化剂活性的影响,并用XRD和EDS技术对催化剂进行表征．结果表明：Mo含量(质量分数)为7．87％的Pt—Ru—Mo／C催化剂的活性为Pt—Ru／C商品催化剂(E—TEK)活性的1．65倍;添加硅钼酸和磷钨酸可以使得活性组分的分散度提高,从而显著提高催化剂的活性和抗毒性能．     

PdCo/C氧还原催化剂及其抗甲醇性能(英文)

以柠檬酸钠为络合剂,在乙二醇体系中采用有机溶胶法制备出了PdCo/C催化剂,XRD研究结果表明催化剂具有面心立方结构,粒度小,分散性好,同时元素钴的加入使催化剂的Pd-Pd间距缩小。采用电化学方法评价了催化剂对于氧气还原反应的活性,结果表明:PdCo/C催化剂具有比Pd/C要好的氧还原活性,同时具有Pt/C催化剂无法比拟的抗甲醇中毒能力。     

乙二胺改性石墨烯载铂催化剂的制备及其电解水制氢的研究

采用乙二胺对氧化石墨烯(GO)进行功能化改性,利用傅里叶变换全反射红外光谱 (ATR FT-IR)、X射线光电子能谱 (XPS) 和透射电镜 (TEM)等测试手段对氧化石墨烯功能化前后的结构进行了定性和定量分析,结果表明功能化石墨烯(FG)中成功的引入了乙二胺。利用功能化石墨烯作为催化剂载体,制备了功能化石墨烯载铂催化剂(Pt/RFG),与商业碳载铂催化剂(Pt/C)进行对比,结果发现铂颗粒在RFG上具有良好的分散性,且平均粒径较小。将这两种催化剂样品分别与全氟磺酸树脂混合制成膜电极,应用于固体聚合物电解水制氢技术,测试其电解去离子水时的电流密度及产氢速率,其中含有Pt/RFG的膜电极电解效率较高,产氢速率可达到2.96 mL/(min·cm²)。     

纳米Pt-Ru/C电催化剂的制备

以炭黑（Vulcan XC72)为载体，将铂钌混合氧化物胶体吸附在炭黑上，然后用氢气还原以制备Pt-Ru/C电催化剂，利用X－射线衍射（XRD）经及X－射线能谱（XPS）技术对样品进行表征，结果表明：在Pt-Ru/C中，面心立方结构中的部分铂原子被钌原子取代，铂钌合金原子的粒子大小在3nm左右，铂钌氧化物吸附在炭黑上后，两种金属的氧化态降低，可以通过氢气鼓泡的方法将其还原。     

有机溶胶法制备Pt/C催化剂的影响因素研究

有机溶胶法制备高分散的Pt/C催化剂是目前制备活性组分高度分散的燃料电池催化剂的一种新方法,本文考察了在有机溶胶法制备催化剂的过程中,碳载体的预处理以及制备条件对催化剂性能的影响,实验结果表明：在适当的温度下对碳载体进行热处理可以显著改善活性组分的分散和提高催化剂的性能;在惰性气氛中还原制得的催化剂的性能明显优于在空气气氛中还原制得的催化剂,较低温度有利于获得活性组分颗粒度较小的催化剂,起始PH值大于10时制得的催化剂的活性明显高于PH小于10时制得的催化剂。采用优化条件制备的Pt/C催化剂对甲醇氧化的电化学性能和抗中毒性能显著优于E-TEK Pt/C催化剂。     

Three-dimensional ordered macroporous platinum-based electrode for methanol oxidation

The attractive application of the direct oxidation methanol fuel cell (DMFC) in wide application areas, such as portable energy and stationary power suppliers, stimulates researchers to search for optimal anodic electrocatalysts for the oxidation of methanol. In prac- tical performance, the catalysts are generally dispersed as nanoparticles for conducting supports with high sur- face area for obtaining maximum catalyst utilization. Porous carbon is one of the well-known supports for the dispe…     

固相反应制备的Pt/C对甲酸氧化的电催化活性

研究了用固相反应法制备的碳载Pt(Pt／C(s))催化剂对甲酸氧化的电催化活性．XRD和TEM的测量表明，Pt／C(s)催化剂中Pt的平均粒径和结晶度远小于用传统的液相反应法制备的碳载Pt(Pt／C(1))催化剂，因此，Pt／C(s)催化剂对甲酸氧化的电催化活性远高于Pt／C(1)催化剂．     

一种新型介孔碳材料的合成与表征

采用具有较高水热稳定性、 较厚孔壁的介孔分子筛MTS-9为模板, 合成一种新型的介孔碳分子筛： C-MTS-9, 并通过X射线粉末衍射、 热重分析、 透射电镜和氮气吸附/脱附等方法对其进行表征. 结果表明, C-MTS-9分子筛具有较高的BET比表面, 孔径达到5 nm, 且孔分布比较均一; 电化学的循环伏安测量表明, C-MTS-9具有较好的电化学性质.