Manufacturing Process of Electrode Films

Abstract

Rotating disk electrode experiments form a key experimental characterization technique for measuring electrocatalyst performance and durability. Numerous studies have been performed to gauge catalyst performance and suitability for polymer electrolyte fuel cells. However, those studies can show for a wide range of performance measurements for the same catalyst.1 Standard rotating disk electrode testing protocols have been documented, and used repeatedly in available literature.1 Little research has been devoted to the catalyst film preparation however. Catalyst films are formed from the drying of a catalyst solution consisting of a catalyst-water-ethanol-Nafion solution on a glassy carbon working electrode surface. Experiments within our group show large variation in catalyst performance characterization for catalyst films dried under ambient conditions, which result from inconsistent and non-uniform catalyst distribution on the electrode surface. To promote consistent film production, a controlled environmental chamber was constructed. The objective of this chamber was to establish conditions for equalizing water and alcohol evaporation in the catalyst solution by controlling relative humidity. Catalyst film quality was shown to improve when using the chamber, improving film catalyst distribution uniformity, along with electrochemical catalyst performance. This paper will detail the construction and the environmental control chamber, and the effect of environmental conditions on the catalyst film quality and electrochemical measurements.Reference1. S. Kocha et al., “Best Practices and Testing Protocols for Benchmarking ORR Activities of Fuel Cell Electrocatalysts Using Rotating Disk Electrode,” Electrocatalysis, vol. 8, no. 4, pp. 366–374, Jul. 2017, doi: 10.1007/s12678-017-0378-6. Figure 1