Fuel cell catalyst cost

He, C., Desai, S., Brown, G., and Bollepalli, S. (2005) PEM fuel cell catalysts cost performance, and durabihty. Electrochemical Society Interface, 14 (3), 41-44. 

Fuel Cell Catalyst OT, °C Carbon Tolerance Life Demonstrated, hr Stack Cost, /kW... 

This approach would also potentially have two other advantages over current technology. First, if platinum loadings could be reduced, it could produce a welcome reduction in the capital cost of fuel cell catalysts. In recent years, prices for platinum have significantly exceeded those for gold... 

From combined theoretical and experimental insights, nanostructured Pt core-shell electrocatalyst architectures have recently emerged as promising, cost-effective cathode fuel cell catalysts. Pt-enriched multilayer surface shells surround Pt-poor cores that modify the reactivity of the surface Pt layer. 

A key to widespread use of fuel cells as a power source is high-performance, low-cost manufacturable electrocatalyst. Ink-jet technology has been used in library preparation for methanol fuel cell catalysts discovery at Penn State University and Illinois Institute of Technology [34]. 

There are several advantages for the use of S-ZrOj as a catalyst support in PEMFC applications. Because of its hydrophilicity, it has been suggested that this type of fuel cell catalyst would be well suited for low-relative humidity conditions and possibly simplify fuel cell components to operate without the use of a humidifier. Due to the proton conductivity across the surface of the material, less Nafion iono-mer needs to be cast to form the TPBs. Platinum utilization increases as the S-ZrOj support acts as both the platinum and proton conductor and better gas diffusion to the catalyst site results from the decreased blockage of Nafion ionomer (Liu et al., 2006a,b). It is beheved that within porous carbon catalyst supports, platinum deposited within the pores may not have proton conductivity due to the perfluorosul-fonated ionomer unahle to penetrate into the pores. Thus, a TPB which is necessary for a catalyst active site will not be formed. Therefore, the S-ZrOj support has an additional benefit over porous carbon material supports in that by using the S-ZrOj as a support for platinum catalysts, the surface of the support can act as a proton conductor and platinum deposited anywhere on the surface of the support will provide immediate access to the electron and proton pathways thereby requiring less Nafion. Thus the use of S-ZrOj in fuel cell MEA components may potentially lower the cost of materials substantially, as the catalytic metals and membrane materials are among the most costly in a PEMFC. However, like most metallic oxides, the downside of their use stems from their relatively low electron conductivity and low surface areas that results in poor platinum dispersion. 

Typical platinum catalyst loadings needed to support the anodic and cathodic reactions are currently 1 to 2 mg/cm" oi active cell area. Owing to the cost of platinum, substantial efforts have been made to reduce the catalyst loading, and some fuel cells have operated at a catalyst loading of 0.25 mg/cm". 

Even in a simple hydrogen fuel cell system, capital cost reduction requires improvements in many diverse areas, such as catalyst loadings, air pressuriza-... 

Although it is attractive to directly convert chemical energy to electricity, PEM fuel cells face significant practical obstacles. Expensive heavy metals like platinum are typically used as catalysts to reduce energy barriers associated with the half-cell reactions. PEM fuel cells also cannot use practical hydrocarbon fuels like diesel without complicated preprocessing steps. Those significantly increase the complexity of the overall system. At this time, it appears likely that PEM fuel cells will be confined to niche applications where high cost and special fuel requirements are tolerable. 

A fuel cell is an electrochemical reactor with an anodic compartment for the fuel oxidation giving a proton and a cathodic compartment for the reaction of the proton with oxygen. Two scientific problems must be solved finding a low-cost efficient catalyst and finding a membrane for the separation of anodic and cathodic compartments. The membrane is a poly electrolyte allowing the transfer of hydrated proton but being barrier for the gases. 

---