DMFCs: From Fundamental Aspects to Technology Development

Abstract

This review paper describes recent developments in both the fundamental and technological aspects of direct methanol fuel cells (DMFCs). Most previous studies in this field have dealt with fundamental aspects, whereas in recent years, the technology of these devices has become the object of significant interest. This is mainly due to the fact that a probable application of DMFCs in portable power sources and in hybrid electrical vehicles has only recently been envisaged. The section on fundamentals is particularly focused on the electrocatalysis of the methanol oxidation reaction and oxygen electroreduction. In this regard, particular relevance is given to the interpretation of the promoting effect on Pt of additional elements and some aspects of the electrocatalysis of oxygen reduction in the presence of methanol crossover have been treated. The technology section deals with the development of both components and devices. Particular emphasis is given to the development of high surface area electrocatalysts and alternative electrolyte membranes to Nafion, also the fabrication methodologies for the M&E assembly have been discussed. The last part of the paper describes the recent efforts in developing DMFC stacks for both portable and electro‐traction applications. The current status of the technology in this field is presented and some important technical and economical challenges are been discussed.

Bimetallic Au-Pt nanoparticles synthesized by radiolysis: Application in electro-catalysis

“…In particular, bimetallic platinumbased catalysts have been proposed as promising alternatives to the exceedingly expensive pure Pt electrocatalysts and are already widely used in industry and for proton exchange membrane (PEM) fuel cells. 1,2 Among numerous possible metal combinations, Au-Pt NPs have been studied intensively because of their optical properties, 3 their potential as selective oxidation 4,5 and dehydrogenation catalysts, 6 electrocatalysts, 7,8,9 and selective sensors. Cationic Au-Pt clusters have shown unique reactivity for C-N coupling of methane and ammonia.…”

Oscillatory instabilities during the electrocatalytic oxidation of methanol on platinum

“…[1][2][3] Limitations associated to the high overpotential and the existence of parallel reaction pathways makes its understanding a rather challenging task. Studies have been carried out mainly on platinum surfaces, both polycrystalline and single crystals, by means of different electrochemical approaches sometimes coupled to other in situ and on line techniques.…”

Nitrogen-Doped Graphene as Efficient Metal-Free Electrocatalyst for Oxygen Reduction in Fuel Cells

“…These results indicate that the N-graphene electrode, The N-graphene electrode was further exposed to fuel molecules (e.g., methanol) and CO to test the possible crossover and poison effects. 38,39 We measured electrocatalytic selectivity of the N-graphene electrode against the electro-oxidation of various commonly used fuel molecules, including hydrogen gas, glucose, and methanol (Figure 4b). Also included in Figure 4b is the corresponding current density (j)Ϫtime (t) chronoamperometric response at a Pt/C electrode for comparison.…”