Use of Polyvinylpyrrolidone (PVP) for Enhancing Activity and Stability of Platinum-Based Electrocatalysts for Fuel Cells
Reference #: 2012-020
Direct-methanol fuel cells or (DMFCs) are a subcategory of proton-exchange fuel cells in which methanol is used as the fuel. DMFCs are useful for many portable power applications and micro power applications such as, laptop computers, cell phones, etc. As a result, DMFCs have been an area of intense research directed toward alternative sources of energy. As a fuel, methanol (MeOH) is advantageous in terms of also being readily available from renewable sources of biomass, such as wood. Thus, the incorporation of DMFCs as alternative energy sources in many systems would reduce reliance on more commonly used energy sources such as oil and naturel gas, rendering DMFCs of considerable interest as a green technology. While having advantageous properties, methanol presents significant challenges in its application to the catalytic reactions necessary for use in DMFCs. Specifically, many catalysts have insufficient activity to completely oxidize MeOH, resulting in by-products of intermediate oxidation such as aldehydes and acids. Researchers at Georgetown University have developed platinum-based electrocatalyst compositions, which have improved characteristics over existing compositions. They discovered that high molecular weight PVP can serve as a molecular switch desorbing at potentials that are needed for fuel cell function and re-adsorbing at potentials that can damage the platinum electrocatalyst. This molecular switch functionality enhances the methanol oxidation via increased water absorption and further stabilizes the platinum by C=O re-adsorption thereby preventing platinum dissolution. By increasing the efficiency, the invention will increase the versatility and potential applications of DMFCs.
Compositions and methods of using high molecular weight polyvinylpyrrolidine (PVP) compositions to enhance platinum-based electrocatalysts for fuel cell applications.
Advantageous properties of the compositions containing platinum-based electrocatalysts and high molecular weight PVP include improved, long-term tolerance of carbon monoxide and improved platinum-based catalyst surface stability when compared with platinum-based electrocatalysts alone.
Stage of Development
The properties of the platinum-based electrocatalysts and the high molecular weight PVP have been studied using electrochemical methods and in situ surface enhanced IR absorption spectroscopy (SEIRAS).
Provisional patent application filed