The oxidation pathways of methanol (MeOH) have been the subject of intense research due to its possible application as a liquid fuel in polyelectrolyte membrane (PEM) fuel cells. The design of improved catalysts for MeOH oxidation requires a deep understanding of these complex oxidation pathways. This paper will provide a discussion of the literature concerning the extensive research carried out in acidic and alkaline electrolytes. It will highlight techniques that have proven useful in the determination of product ratios, analysis of surface poisoning, anion adsorption, and oxide formation processes, in addition to the effects of temperature on the MeOH oxidation pathways at bulk polycrystalline platinum (Ptpoly) electrodes. This discussion will provide a framework with which to begin the analysis of activation energy (Ea) values. This kinetic parameter may prove useful in characterizing the rate-limiting step of the MeOH oxidation at an electrode surface. This paper will present a procedure for the determination of Ea values for MeOH oxidation at a Ptpoly electrode in acidic and alkaline media. Values from 24–76 kJ mol−1 in acidic media and from 36–86 kJ mol−1 in alkaline media were calculated and found to be a function of applied potential and direction of the potential sweep in a voltammetric experiment. Factors that influence the magnitude of the calculated Ea include surface poisoning from MeOH oxidation intermediates, anion adsorption from the electrolyte, pH effects, and oxide formation processes. These factors are all potential, and temperature, dependent and must clearly be addressed when citing Ea values in the literature. Comparison of Ea values must be between systems of comparable electrochemical environment and at the same potential. Ea values obtained on bulk Ptpoly, compared with other catalysts, may give insight into the superiority of other Pt-based catalysts for MeOH oxidation and lead to the development of new catalysts which lower the Ea barrier at a given potential, thus driving MeOH oxidation to completion.

Electrochemical determination of activation energies for methanol oxidation on polycrystalline platinum in acidic and alkaline electrolytes

Three periods of Pt–Ru research are considered step-by-step: the initial period after discovery (1963–1970); observation and classification of basic tendencies (like the effects of composition, segregation, structural features on the activity; up to 1990); nanostructural studies and molecular level consideration of electrocatalytic phenomena in combination with advanced applied studies of materials, mechanistic, and applied aspects (after 1990). The main idea of this review is to balance various aspects of Pt–Ru electrochemistry related to material science and electrocatalysis as well as to remember the early basic results being of importance for future understanding of Pt–Ru functional properties.

Pt–Ru electrocatalysts for fuel cells: a representative review

The particle size effect observed on the performance of Pt/C electrocatalysts toward the methanol oxidation reaction (MOR) has been investigated with differential electrochemical mass spectrometry (DEMS). The investigation has been conducted under both potentiodynamic and potentiostatic conditions as research on methanol electrochemical oxidation is closely related to interest in direct methanol fuel cells. The particle size effect observed on the MOR is commonly regarded as a reflection of different Pt-CO and Pt-OH bond strengths for different particle sizes. This work focuses mainly on the mechanism of methanol dehydrogenation on platinum which is central to the problem of the optimization of the efficiency of methanol electro-oxidation by favoring the CO(2) formation pathway. It was found that the partitioning of the methanol precursor among the end products on supported platinum nanoparticles is strongly dependent on particle size distribution. Also, it is postulated that the coupling among particles of different sizes via soluble products must be considered in order to understand the particle size effects on the observed trends of product formation. An optimum particle size range for efficiently electro-oxidizing methanol to CO(2) was found between 3 and 10 nm, and loss in efficiency is mostly related to the partial oxidation of methanol to formaldehyde on either too small or too large particles. The possible reasons for these observations are also discussed.

Nanoparticle Size Effects on Methanol Electrochemical Oxidation on Carbon Supported Platinum Catalysts

A new two-dimensional model of a direct methanol fuel cell (DMFC) has been developed and numerically tested. In complement to the existing developments, this model regards the diffusion layers as water-gas systems in the pore space with saturation and permeability varying according to capillary effects. The presence of hydrophilic and hydrophobic pores has been taken into account by introducing a new parametrization of the relationship between capillary pressure and saturation. Thus, mass transport occurs in parallel in the two phases, gas and liquid. The exchange between these phases is due to condensation and evaporation with rates given by the available exchange surface and the temperature. The gas transport is governed by the Stefan-Maxwell equations incorporated into the two-phase flow modeling approach. Instead of the often used Tafel and Butler-Volmer equations which are insufficient in the case of catalytic methanol oxidation and oxygen reduction, according to recent investigations, the electrochemical reactions are split up into reaction chains involving the covering of the catalysts with the various intermediate species. The main advantage of this approach is that it incorporates the effects of the limitation of the reaction rates due to the limited number of catalyst sites in a natural manner. The resulting system of transport and reaction equations is discretized in time by the backward Euler method and in space by a finite volume technique with proper upwinding.

Performance Modeling of a Direct Methanol Fuel Cell

1. Energy Conservation and Environmental Friendliness-the Incentive for Fuel Cell Development The fuel cell is a nineteenth century invention; in the twentieth century it became the “heart” of an electrochemical power plant and power source, which is now in a stage of advanced technology development. Its first and only application since the early 1960s, has been as an auxiliary power source for space flights by the National Aeronautics and Space Administration (NASA). During the past decade, development for terrestrial (civilian and defense) applications has led to its commercialization and research on utilization in a variety of applications. Programs in the United States, Japan, Europe, and some other countries are focused on the development of fuel cell power plant/power sources for (1) base-load,

Direct Methanol Fuel Cells: From a Twentieth Century Electrochemist’s Dream to a Twenty-first Century Emerging Technology

Kinetics of methanol oxidation on carbon-supported Pt and Pt + Ru catalysts

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

J. Munk

Author Tools

Chat about Author

Papers

Kinetics of methanol oxidation on carbon-supported Pt and Pt + Ru catalysts