Deployment of polymer electrolyte fuel cell vehicles commercially requires the development of a robust hydrogen fueling infrastructure. This is coupled with the need for high purity hydrogen fuel necessary to maintain fuel cell engine performance and durability over the life of the vehicle. In this paper, we discuss the development of an electrochemical hydrogen contaminant detector (HCD) to sense the presence of impurities in hydrogen fuel. Specifically, the role that mass transport plays on the HCD response is discussed. Electrolyte development is highlighted, in with focus on the effects of thickness on detecting the presence of contaminants. Further work on humidity independent electrolytes is provided, along with a brief discussion on the response measured during high pressure testing.

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. Reference 1. 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

Rotating disk electrode (RDE) experiments form a key experimental characterization technique for measuring electrocatalyst performance and durability. While standard RDE testing protocols have been documented, it has been noted that catalyst film quality can skew measurements. The impact of relative humidity on drying is studied in an effort to produce consistent, high quality catalyst films for RDE experiments, which shows that high quality catalyst films can be manufactured repeatedly in a controlled environment, such as inside an environmental chamber as described.