Fabrication and Characterization of Electro-catalyst and Electrolyzer Components for Hydrogen Production
LaboratorySavannah River National Laboratory (SRNL)
Capability ExpertHéctor Colón-Mercado
Process and Manufacturing Scale-Up
Node Readiness Category1: Hybrid Thermochemical (HT)
Previous capability name: "Characterization of High Temperature Catalyst and Electrolyzer Components for Hydrogen Production."
This capability consists of the fabrication of membrane electrode assemblies (MEAs), high throughput catalyst screening of thin films prepared through physical vapor deposition, catalyst synthesis, and characterization of MEAs and individual components using electrochemical methods. Once the components are synthesized and fabricated, a suite of characterization techniques are used to determine component properties such as catalytic activity, performance stability, membrane transport properties (e.g., SO2 cross-over, ionic conductivity) in simulated acid solutions. This capability includes a multi-gun sputter deposition chamber, a membrane test setup, catalyst test setup, and a custom-built Button Cell Test Facility (BCTF) designed to withstand operation with highly corrosive acid environments and harsh chemicals (such as conc. H2SO4, SO2, etc.) at elevated temperatures. This allows the electrochemical evaluation of various components under a variety of electrolyzer relevant conditions. The BCTF is a specialized facility designed to test novel materials such as high temperature proton exchange membranes and electrocatalysts for H2 production through non-conventional electrolysis systems. Because of its small cell area, small membrane and catalyst prototype samples can be tested at simulated system operating conditions.
The BCTF is limited to membrane electrode assemblies with electrode surface area of approximately 5cm2 with membrane surface area up to 10cm2. Operating conditions such as current and temperature are limited to 5A, 1.5V and 130°C, respectively. The individual membrane and catalyst screening setup is limited to operation at atmospheric pressures.
The membrane and catalyst test setups are used in conjunction with the BCTF to acquire individual and collective properties of the electrolyzer components. The BCTF facilitates testing of anode electrocatalysts and high temperature membranes at electrolyzer relevant conditions. This includes corrosive environments, such as sulfuric acid saturated with sulfur dioxide, at temperatures up to 130°C. BCTF construction materials consist of zirconium, tantalum, fluoropolymers, graphite, and glass.
SRNL currently has one BCTF, one membrane test station, and two catalyst screening set-ups; (three-electrode electrochemical cells). This equipment is at the disposal of the PI with minimal facility access training.
BCTF in combination with the membrane and catalyst test stations can be used to test catalysts, membranes, and membrane electrode assemblies at realistic operating conditions. It expands the hydrogen production research by electrolysis to other water-based chemistries other than acid or alkaline water electrolysis.
Figure 1. BCTF for testing membrane electrode assemblies with SO2 and water.
Summers, W., Colón-Mercado, H. R., Gorensek, G., Corgnale, C., Elvington, M. "Electrolyzer Component Development for the HyS Thermochemical Cycle." 2016 Annual Merit Review Proceedings Hydrogen Production and Delivery. DOE Hydrogen and Fuel Cells Program, n.d. Web. 31 Aug. 2016
Fuentes, R. E., Colón-Mercado, H. R., Martínez-Rodríguez, M. J. (2014). “Pt-Ir/TiC electrocatalysts for PEM fuel cell/electrolyzer process.” Journal of The Electrochemical Society, 161 (1) F77-F82
Elvington, M. C., Colón-Mercado, H., McCatty, S., Stone, S. G., & Hobbs, D. T. (2010). “Evaluation of proton-conducting membranes for use in a sulfur dioxide depolarized electrolyzer.” Journal of Power Sources, 195(9), 2823-2829.