Materials Science and Engineering Commons^™

Preparation And Catalytic Properties Of Feco Alloy Nanocatalyst, Ming-Xuan Li, Jie-Lian Ou, Sheng-Pei Chen, Peng Wang, Bin-Bin Xu, Shi-Gang Sun

Journal of Electrochemistry

The FeCo alloy nanoparticles were electrodeposited on glassy carbon electrode by chronoamperometry and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the shapes of FeCo nanoparticles were cubes with an average size of 65 nm. The atom ratio of Fe and Co is 1:1. As indicated from the pattern of selected area electron diffraction (SAED), the FeCo cubic nanoparticles were single crystal which belonged to body-centered cubic with an interval of 0.201 nm referring to the (110) facets of FeCo alloy. The FeCo cubic nanoparticles exhibited the enhanced electrocatalytic …

Oxygen Reduction Reaction On Glycin Modified Pt(111) Electrode, Ming-Fang Li, Jing Kang, Ling-Wen Liao, Yan-Xia Chen, Shen Ye

Journal of Electrochemistry

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xygen reduction reaction (ORR) on glycin (NH₂CH₂COOH) modified Pt(111) electrode has been investigated using hanging meniscus rotating disk electrode system (HMRD) in 0.05 mol•L^-1 H₂SO₄ and 0.1 mol•L^-1 HClO₄ solutions, respectively. Cyclic voltammograms of the glycin modified Pt (111) electrode measured in 0.05 mol•L^-1 H₂SO₄ solution similar to that of CN^- modified Pt(111) electrodes, demonstrating that sulfate adsorption is strongly inhibited at the glycin modified Pt(111). From the polarization curve of ORR recorded in 0.05 mol•L^-1 H₂SO₄ solution, it is …

Ternary Alloy Electrocatalysts For Oxygen Reduction Reaction, Jin Luo, Lefu Yang, Binghui Chen, Chuanjian Zhong

Journal of Electrochemistry

Proton exchange membrane fuel cell represents an important electrochemical energy conversion device with many attractive features in terms of efficiency of energy conversion and minimization of environmental pollution. However, the large overpotential for oxygen reduction reaction at the cathode and the low activity, poor durability and high cost of platinum-based catalysts in the fuel cells constitute a focal point of major barriers to the commercialization of fuel cells. The development of nanostructured catalysts shows promises to addresses some of the challenging problems. The ability to engineer the composition and nanostructure of nanoalloy catalysts is important for developing active, robust and …

Methodological Significance Of "Property-Activity Relationship" For Catalyst Studies, Jun-Tao Lu, Li Xiao, De-Li Wang, Yu-Bao Sun, Yan-Ge Suo, Lin Zhuang

Journal of Electrochemistry

Instead of attempting the structure-activity relationship (SAR), which is commonly regarded as the core problem for catalyst studies, this paper highlights the methodological significance of “property-activity relationship (PAR)”. The “property” here refers to an index （such as the adsorption energy of an intermediate） or a group of indexes reflecting the behavior of a catalyst which interacts with reactants or intermediates, and is a bridge between structure and activity. Because property is related to activity more directly than structure to activity, PAR should be simpler, less difficult and, therefore, more feasible to be accessed than SAR. Once the key property is …

Catalytic Activities Of Electrochemically Dealloyed Pt(Pd)-Cu Catalysts For Oxygen Reduction Reaction, Rui-Zhi Yang, Strasser Peter, Toney Michael

Journal of Electrochemistry

The electrochemically dealloyed Pt(Pd)-Cu catalysts were prepared by electrochemical dealloying of Cu₃Pt(Pd) and their catalytic activities toward oxygen reduction reaction (ORR) were studied in 0.1 mol·L^-1 HClO₄ . solutions. The structural features of the dealloyed Pt(Pd)-Cu were revealed by synchrotron-based anomalous X-ray diffraction (AXRD) and surface X-ray scattering (SXS) at an atomic scale. We established a relationship between the structure and the catalytic activity by comparing the ORR activity and the structure of dealloyed Cu₃Pt nanoparticles with similarly dealloyed Cu₃Pt thin films and Cu₃Pt(111). The enhancement in the activity of …

Synthesis And Electrocatalytic Properties Of Ni-Pd/C Catalysts With Pd-Enriched Surface, Yu-Mei Chen, Zhi-Xiu Liang, Sheng-Li Chen

Journal of Electrochemistry

The Ni-Pd alloy catalysts with Pd-enriched surface were synthesized through a modified polyol process.The synthesized materials were investigated by XRD and electrochemical methods,and tested as electrocatalysts for CH₃OH-tolerant oxygen reduction.The results indicated that the synthesized Ni-Pd nanoparticles possess multiple phases containing Pd-Ni alloy and pure Ni.Comparing with Pd/C,the prepared Ni-Pd/C nanoparticles exhibited better resolved voltammetric peaks between the hydrogen absorption and adsorption,and positively shifted current peaks for the reduction of Pd oxide.The prepared Ni-Pd alloys with Pd-enriched surface have significantly enhanced ORR activity and improved CH₃OH tolerance as comparing with Pd/C catalysts.

Electrocatalysis In Polymer Electrolyte Membrane Fuel Cells, Li Li, Si-Guo Chen, Xue-Qiang Qi, Yao-Qiong Wang, Meng-Bo Ji, Lan-Lan Li, Zi-Dong Wei

Journal of Electrochemistry

This review presents the study of Chongqing University in electrocatalysis for polymer electrolyte membrane fuel cells(PEMFCs).Based on the understanding to the performance degradation of PEMFCs' catalysts,the university has being concentrated on how to increase the activity,stability and utility of noble metal catalysts.It covers the molecular design of near-surface alloy catalysts for improvement of activity to oxygen reduction reaction(ORR) and resistance to foreign poison species,selective deposition of Pt on the so-called "three-phase interface" for a high Pt utility,and invention of anti-flooding electrode against water flooding in the catalyst layer of the membrane assemble electrode(MEA),and so on.The catalytic mechanism of electrode reactions …

Effect Of Impurity Cu(2+) On Oxygen Electrode In Pemfc, Xiao Jie, Jun-Bo Hou, Zhi-Gang Shao, Bao-Lian Yi

Journal of Electrochemistry

Rotating disk electrode was adopted in this paper to simulate the cathode in PEMFC.In the Cu²⁺ electrolyte,the influence of impurity Cu²⁺ on Carbon-Supported Pt Catalysts was investigated by using electrochemical measurements such as chronocoulometry,cyclic voltammetry and linear sweep.Experimental results showed that,after constant voltage at 0.49 V,the ECA of Pt/C decreased dramatically,it's perhaps under potential deposition of Cu might occur on the substrate.Meanwhile the change of ORR Tafel scope reaction is very large.It might be because oxygen adsorption sites are occupied by Cu atoms after they under potential deposit on surface of Pt/C catalyst,and the adsorption of oxygen on …

Ceo2/Pt Composite Electrodes And Their Catalytic Performance, Ying Fu, Zi-Dong Wei, Yong-Chao Feng, Xin-Li Ma, Ming-Jia Liao, Chao Liao, Jie Zhang, Huan Zhang

Journal of Electrochemistry

In this paper,the cerium oxide(CeO₂) nanoparticles were electrochemically deposited on a Pt electrode by potentiostatic deposition(psd) and potential pulse deposition(ppd) to form CeO₂/Pt composite electrodes,CeO₂/Pt(psd) and CeO₂/Pt(ppd).The properties of the CeO₂ were characterized by field emission scanning electron microscope(FESEM) and X-ray diffraction(XRD).The results showed that the CeO₂ nanoparticles prepared by psd and ppd were homogeneous and dense.The methanol oxidation reaction(MOR) and oxygen reduction reaction(ORR) on the Pt electrode were enhanced with the introduction of CeO₂ into Pt.In addition,the catalytic capability of the CeO₂/Pt electrode can be further …

Studies Of Surface Diffusion In Pemfc Electrodes, Jiang-Shui Luo, Jian Chen, Bao-Lian Yi, Chuan-Sin Cha, Hua-Min Zhang

Journal of Electrochemistry

A PEMFC electrode consisting of dual-layer catalyst layer(CL) was fabricated in this work. The outer CL was Nafion-free,while the inner CL was Nafion-bonded. The effects of Pt/C catalyst in the outer CL that did not contact with Nafion on the current generation in PEMFC electrodes were investigated. Cyclic voltammetric studies indicated that the Pt/C catalyst in the outer CL without direct contact with Nafion was still electrochemically active in taking part in the adsorption/desorption of hydrogen and the electrochemical oxidation/reduction of the oxygen-containing species occurring at the interface of "Pt/Nafion" in the inner CL. The polarization curves showed that the …