G.H. Miley, S.N. Srivastava, G. Chen
UiUC/NPL Associates, United States
pp. 49 - 52
Keywords: PEM fuel cell, plasma treatment, catalyst
Polymer Electrolyte Membrane (PEM) fuel cell electrocatalysts are composed of noble metals (e.g. platinum), which are scarce and expensive. A simple plasma-surface modification method is described to increase the performance of PEM fuel cell catalytic materials. This plasma modification increases the number of reaction sites on the catalyst and also increases the reactivity achieved on the sites. The physics behind the plasma modification of catalytic surfaces can be explained through structural changes created by the plasma bombardment. PEM fuel cell electrocatalysts are kown to be structure-sensitive. For example the catalytic activity of platinum and platinum-nickel alloys change with crystal structure and surface formation. This confirms that certain small local structures on the surface are where reactions take place. The work described here uses a plasma-surface treatment to enhance catalytic performance. This uses a prescribed exposure to low temperature glow discharge plasma such that additional nanostructured sites are created on the surface and in addition the activity of existing sites is improved. This plasma-surface modification method is being explored for use with less expensive heterogeneous catalytic material (e.g. nickel, copper, titanium, etc.) which could replace the more expensive noble metal catalysis commonly used in present PEM fuel cells.