Proton-Exchange Membrane Fuel Cells with Low-Pt Content

Abstract

Widespread commercialization of fuel cell electric vehicles (FCEV) relies on further reduction of PGM (platinum group metals) usage. Although enhancements in the activity and stability of the catalyst are necessary, those alone are insufficient. In a fuel cell with low PGM content, transport of reactants (oxygen and protons) to a small area of catalyst can cause large performance loss at high power. Because it is this high-power point that determines the required fuel cell area, these losses drive up the size, and thus the cost, of the fuel cell stack. This entry discusses fuel cell cost reduction with special focus on the challenges and opportunity associated with Pt reduction. Proton-Exchange Membrane Fuel Cells with Low-Pt Content, Fig. 1 Impact of fuel cell vehicles on Pt consumption (Reprinted with permission from Ref. [7].

Physically Based Modeling of PEMFC Cathode Catalyst Layers: Effective Microstructure and Ionomer Structure–Property Relationship Impacts

“…Electrodes with lower Pt loadings exhibit large transport losses that are not yet sufficiently explained in the literature [13]. Some researchers propose resistances at the ionomer/gas interface and ionomer/Pt interface as a source of these resistances [14,15], although other work suggests limited impact for the former [16]. Although incorporating these resistances provides reasonable agreement to data for existing models, their cause is not yet fully understood.…”

Boosting Fuel Cell Performance with Accessible Carbon Mesopores

“…Heavy use of scarce Pt in the electrodes poses a barrier to the application of proton exchange membrane fuel cells (PEMFCs) for transportation. Although some automakers can now commercialize fuel cell electric vehicles (FCEVs) with as little as 30 g of Pt, − this is still substantially more than what incumbent internal combustion engine vehicles use (2–8 g of precious metals). A long-term target of <5 g of Pt-group metals per vehicle is probably needed to be sustainable. , Since W. R. Grove’s invention of the fuel cell in 1839, , most breakthroughs in fuel cell performance have been associated with an increase in the so-called three-phase interfacethe interface where the reactant gas meets electrons in the solid phase and protons in the electrolyte phase.…”

“…Although some automakers can now commercialize fuel cell electric vehicles (FCEVs) with as little as 30 g of Pt, − this is still substantially more than what incumbent internal combustion engine vehicles use (2–8 g of precious metals). A long-term target of <5 g of Pt-group metals per vehicle is probably needed to be sustainable. , Since W. R. Grove’s invention of the fuel cell in 1839, , most breakthroughs in fuel cell performance have been associated with an increase in the so-called three-phase interfacethe interface where the reactant gas meets electrons in the solid phase and protons in the electrolyte phase. Pt is made into nanoparticles and supported on carbon black to increase the mass-specific Pt surface area and to secure large pores for reactant oxygen gas to access Pt .…”

Macromolecular antioxidants for chemically durable polymer electrolyte fuel cell membranes

“…First, the radical attacks a carboxylic acid end group ( COOH) of the polymer main chain, which is the weakest part of the structure in terms of bonding due to the so-called non-stabilized PFSA. 15 As described in Equations (1) to (3), hydroxyl radicals attacking the carboxylic acid end groups produce CO 2 and HF and reform COOH. These reactions propagate along the main chain followed by the constant loss of CF 2 , which is known as the "unzipping" mechanism.…”

“…Polymer electrolyte membrane fuel cells (PEMFCs) are a viable option for green power generation to realize a clean environment. 1 However, their use remains limited due to their high costs and low component durabilities. 2 Issues related to fuel cell durability are mainly due to membrane electrode assembly (MEA) failure.…”