Ni hollow spheres as catalysts for methanol and ethanol electrooxidation

In this paper, we successfully synthesized Ni hollow spheres consisting of needle-like nickel particles by using silica spheres as template with gold nanoparticles seeding method. The Ni hollow spheres are applied to methanol and ethanol electrooxidation in alkaline media. The results show that the Ni hollow spheres give a very high activity for alcohol electrooxidation at a very low nickel loading of 0.10 mg cm⁻². The current on Ni hollow spheres is much higher than that on Ni particles. The onset potential and peak potential on Ni hollow spheres are more negative than that on Ni particles for methanol and ethanol electrooxidation. The Ni hollow spheres may be of great potential in alcohol sensor and direct alcohol fuel cells.     

Remarkable support effect of SWNTs in Pt catalyst for methanol electrooxidation

Carbon nanotubes have been proposed as advanced metal catalyst support for electrocatalysis. In this work, different carbon support materials including single-walled carbon nanotubes (SWNTs), multi-walled carbon nanotubes (MWNTs) and XC-72 carbon black, were compared in terms of their electrochemical properties using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The SWNTs is found to exhibit the highest accessible surface area in electrochemical reactions and the lowest charge transfer resistance at the SWNTs/electrolytes. These carbon materials are then loaded with varying amount of Pt by the electrodeposition technique to prepare carbon supported Pt catalysts. Electrochemical measurements of methanol oxidation reveal that the SWNTs supported Pt catalyst exhibits the highest mass activity (mA/mg-Pt). In comparison with Pt-XC-72 and Pt-MWNTs, the remarkably enhanced electrocatalytic activity of the Pt-SWNTs maybe attributed to a higher dispersion and utilization of the Pt particles, which are directly related to the electrochemical characteristics of SWNTs. The high concentration of oxygen-containing functional groups, high accessible surface area, low charge transfer resistance at the carbon/electrolyte interfaces can be important for the Pt dispersing and strong metal-support interaction in the Pt-SWNTs catalyst.     

Synthesis of mesoporous hollow carbon hemispheres as highly efficient Pd electrocatalyst support for ethanol oxidation

The synthesis procedure of the highly mesoporous hollow carbon hemispheres (HCHs) using glucose as carbon source and solid core mesoporous shell silica (SCMSS) as template and the formation mechanism of the HCHs have been presented. The HCHs show an ultrahigh surface area of 1095.59 m² g^?1 and an average mesopore size of 9.38 nm. The hemispherical structure with large mesopores also results in the improvement in the mass transfer and therefore more concentrated ethanol solution can be used to increase the energy density. The additional advantage of the HCHs compared to the hollow carbon spheres is that they can provide the similar surface area at reduced volume. The current densities of ethanol oxidation on Pd nanoparticles supported on HCH (Pd/HCH) electrocatalyst are three times as many as on Pd/C at the same Pd loadings.     

Synthesis of mesoporous PtCu film modified with Ru submonolayer as catalyst for methanol electrooxidation

A mesoporous PtCu catalyst modified with a Ru submonolayer is successfully synthesized by a facile electrochemical process of electrodeposition, dealloying and Ru underpotential deposition. The material has a large specific surface area comparable to nanoparticles (11 m(2) g(-1)) and exhibits a promising catalyst activity for the methanol oxidation reaction.     

Preparation of Pd/MgO-reduced graphene oxide hybrid catalyst and enhanced activity for methanol electrooxidation

Magnesium oxide modified reduced graphene oxide supported Pd nanocatalyst (Pd/MgO-RGO) was facilely prepared by a chemical approach. The as-prepared material was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray diffraction. The electrocatalytic behavior of Pd/MgO-RGO for methanol oxidation was studied using cyclic voltammetric and chronoamperometric methods. The results indicated that Pd/MgO-RGO nanocatalyst exhibits higher electrocatalytic activity and better stability than Pd/RGO.     

Conducting polymeric nanotubules as high performance methanol oxidation catalyst support

Pt nanoparticle-supported conducting nanotubules of polypyrrole prepared by a template method exhibited excellent catalytic activity and stability for the electrooxidation of methanol in comparison to Pt supported on conventionally synthesised conducting polypyrrole.     

花生壳基多孔碳负载Pd-Co催化剂应用于碱性介质中电氧化甲醇

以花生壳为原料,经KOH活化制备花生壳基多孔碳（HC）。氮气吸附-脱附研究表明,所获得的多孔碳的总表面积高达1 645 m²·g^-1。采用浸渍还原法制备了以HC为载体的Pd-Co/HC催化剂。X射线衍射（XRD）和X射线光电子能谱（XPS）分析表明,催化剂中的Co主要以Co和CoO的形式存在,Co进入Pd的晶格并形成Pd-Co合金。Pd-Co/HC_0.5-700的透射电子显微镜（TEM）结果显示,Pd-Co纳米颗粒具有较小粒径（约4 nm）且成功地分散在HC上。Pd-Co/HC_0.5-700在碱性介质中电催化氧化甲醇时表现出优秀的电催化活性、稳定性和CO耐受性,这种显著的高性能可以归因于生物质载体大的表面积和Co的成功掺杂。     

花生壳基多孔碳负载Pd-Co催化剂应用于碱性介质中电氧化甲醇

以花生壳为原料,经KOH活化制备花生壳基多孔碳(HC)。氮气吸附-脱附研究表明,所获得的多孔碳的总表面积高达1 645 m²·g^-1。采用浸渍还原法制备了以HC为载体的Pd-Co/HC催化剂。X射线衍射(XRD)和X射线光电子能谱(XPS)分析表明,催化剂中的Co主要以Co和Co O的形式存在,Co进入Pd的晶格并形成Pd-Co合金。Pd-Co/HC_0.5-700的透射电子显微镜(TEM)结果显示,Pd-Co纳米颗粒具有较小粒径(约4 nm)且成功地分散在HC上。Pd-Co/HC_0.5-700在碱性介质中电催化氧化甲醇时表现出优秀的电催化活性、稳定性和CO耐受性,这种显著的高性能可以归因于生物质载体大的表面积和Co的成功掺杂。     

Synthesis,characterization and electrocatalytic properties of carbon nitride nanotubes for methanol electrooxidation

In this paper, carbon nitride nanotubes (CNNTs) have been synthesized with porous anodic aluminum oxide membrane as template by the thermal polymerization of sol–gel precursors for the first time. Field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, elemental analysis and X-ray photoelectron spectroscopy were applied to characterize the morphology and composition of the as-prepared nanotubes. The electrocatalytic activity and stability of CNNTs, towards methanol electrooxidation in 0.5 mol/dm³ H₂SO₄ solutions containing 1 mol/dm³ CH₃OH are presented at room temperature.     

Polyoxometalate-modified carbon nanotubes: new catalyst support for methanol electro-oxidation

A new catalyst support, polyoxometalate-modified carbon nanotubes, is presented in this paper through the chemisorption between polyoxometalate and carbon. Pt and Pt-Ru nanoparticles were electrochemically deposited on polyoxometalate-modified carbon nanotubes electrodes, and their electrocatalytic properties for methanol electro-oxidation are investigated in detail. Due to the unique electrical properties of carbon nanotubes and the excellent redox properties and the high protonic conductivity of polyoxometalate, for the similar deposition charge of Pt and Pt-Ru catalysts, 1.4 times larger exchange current density, 1.5 times higher specific activity, and better cycle stabilities can be obtained at polyoxometalate-modified carbon nanotube electrodes as compared to the electrodes without polyoxometalate modification. These results show that polyoxometalate-modified carbon nanotubes as a new catalyst support have good potential application in direct methanol fuel cells.     

硼掺杂碳化硅负载Pt催化剂的甲醇电催化氧化性能

以硼掺杂碳化硅(B0.1SiC)为载体,采用循环伏安法在B0.1SiC载体上电沉积Pt纳米粒子制备了Pt/B0.1SiC催化剂。利用X射线光电子能谱、X射线衍射、氮气吸附-脱附、扫描电镜及透射电镜等测试方法对催化剂的晶型、表面性质及形貌进行了表征。结果表明,硼原子掺杂进入SiC晶格并取代了Si位点,使B0.1SiC载体的导电性增强;Pt纳米粒子均匀地分布在B0.1SiC载体上,平均粒径为2.7 nm。与相同条件下制备的Pt/SiC催化剂相比,Pt/B0.1SiC具有较大的电化学活性表面积、更高的甲醇催化氧化活性和稳定性。     

Highly dispersed MoO(x) on carbon nanotube as support for high performance Pt catalyst towards methanol oxidation

HPMo self-assembly on carbon nanotubes followed by decomposition is used to fabricate highly dispersed MoO(x)/CNTs as a support for high performance of a Pt catalyst towards methanol oxidation.     

具有优异甲醇催化氧化性能的Pt/MoO3-WO3/CNTs催化剂

以聚二烯丙基二甲基胺盐酸盐(PDDA)为连接剂,采用原位自组装方式将MoO3和WO3负载到碳纳米管(CNTs)上,然后通过乙二醇还原法负载Pt纳米颗粒,得到Pt纳米颗粒均匀分布的Pt/MoO3-WO3/CNTs催化剂.当氧化物总量控制在10 wt%,MoO3与WO3摩尔比为1:0.5时,Pt/MoO3-WO3/CNTs催化剂催化甲醇氧化活性最高,甲醇氧化峰电流If高达835 A/gPt.WO3和MoO3的加入提高了催化剂的甲醇氧化活性、抗CO中毒能力和稳定性,使得Pt/MoO3-WO3/CNTs催化剂表现出优异的甲醇电催化氧化性能.     

Advanced heterostructure of Pd nanosheets@Pt nanoparticles boosts methanol electrooxidation

Heterostructures have emerged as elaborate structures to improve catalytic activity owing to their combined surface and distinct inverse interface. However, fabricating advanced nanocatalysts with facetdependent interface remains an unexploited and promising area. Herein, we render the controlled growth of Pt nanoparticles(NPs) on Pd nanosheets(NSs) by regulating the reduction kinetics of Pt²⁺with solvents. Specifically, the fast reduction kinetic makes the Pt NPs uniformly deposited ...     

Spherical carbon capsules with hollow macroporous core and mesoporous shell structures as a highly efficient catalyst support in the direct methanol fuel cell

Carbon capsules with hollow core and mesoporous shell (HCMS) structures were used as a support material for Pt(50)-Ru(50) catalyst, and the catalytic performance of the HCMS supported catalyst in the direct methanol fuel cell was described; the HCMS carbon supported catalysts exhibited much higher specific activity for methanol oxidation than the commonly used E-TEK catalyst by about 80%, proving that the HCMS carbon capsules are an excellent support for electrode catalysts in DMFC.     

Hollow carbon spheres with wide size distribution as anode catalyst support for direct methanol fuel cells

Hollow carbonaceous composites (HCCs) possessing sphere and hemisphere shape, which had wide size distribution between several tens of nanometers and several micrometers, were prepared through a facile hydrothermal method using glucose as carbon source with the assistance of sodium dodecyl sulfate (SDS). Pyrolysis of these hollow carbonaceous composites at 900 °C under nitrogen flow produced carbonized hollow carbon spheres (HCSs) without changing their structures. Platinum (Pt) was directly deposited on the surface of the HCSs by incipient wet method, using the NaBH₄ as the reductant. TEM, SEM, powder XRD and FT-IR were utilized to characterize all these samples. It was found that Pt nanoparticles were uniformly anchored on the outer and the inner surface of HCSs. The electrocatalytic properties of the Pt/HCS electrode for methanol oxidation have been investigated through cyclic voltammetry and chronoamperometry. The Pt/HCS electrode showed significantly higher electrocatalytic activity and more stability for methanol oxidation compared with Pt supported carbon microspheres (Pt/CMs) and commercial carbon (Pt/XC-72) electrode. The excellent performance for the Pt/HCS might be attributed to the high dispersion of platinum catalysts and the particular hollow structure of HCSs.     

Cuboctahedral Pd nanoparticles on WC for enhanced methanol electrooxidation in alkaline solution

We report cuboctahedral Pd nanoparticles on WC synthesized by the polyol process using ethylene glycol with NO(3)(-) and Fe(3+)/Fe(2+) ions. The cuboctahedral Pd/WC shows much improved electrocatalytic activity for methanol electrooxidation in alkaline solution.     

Pd nanowire arrays as electrocatalysts for ethanol electrooxidation

Highly ordered Pd nanowire arrays were prepared by template-electrodeposition method using anodic aluminum oxide template. The Pd nanowire arrays, in this paper, have high electrochemical active surface and show excellent catalytic properties for ethanol electrooxidation in alkaline media. The activity of Pd nanowire arrays for ethanol oxidation is not only higher that of Pd film, but also higher than that of commercial E-TEK PtRu(2:1 by weight)/C. The micrometer sized pores and channels in nanowire arrays act as structure units. They make liquid fuel diffuse into and products diffuse out of the catalysts layer much easier, therefore, the utilization efficiency of catalysts gets higher. Pd nanowire arrays are stable catalysts for ethanol oxidation. The nanowire arrays may be a great potential in direct ethanol fuel cells and ethanol sensors.