The development of catalysts for the electrochemical processes of hydrogen systems (e.g. fuel cells and electrolyzer systems) continues to be a significant area of research for renewable energy technologies. One significant challenge has been the development of hydrogen catalysts that can be utilized in alkaline environments as the kinetics of hydrogen reactions decrease by two orders of magnitude in alkaline environments compared to acidic^[1,2]. Chemical vapor deposition (CVD) is a conventional tool used in the synthesis of such catalysts^[3,4]. This presentation discusses the extending work being done using a variant CVD process known as “Poor Man’s” CVD (PMCVD), to further its impact in electrochemical catalyst application^[5]. PMCVD is utilizes an inexpensive vacuum oven to sublime commercially available metal-organic precursors; lowering synthesis cost while providing increased control of particle size and distribution. This work describes the work done to assess the PMCVD mechanisms as well as its use to develop catalysts for the hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) in alkaline environments.

Preliminary studies have shown that PMCVD can develop catalysts with highly dispersed nanoparticles on various supports. As depicted in Figure 1, PMCVD synthesized Pt/C and PtRu/C catalysts have shown to have improved kinetics over commercial developed catalysts exhibiting approximately a 40% and 45% increase in average exchange current densities respectively when compared to Tanaka Kikinzoku catalysts of the same loading. An extended function of the PMVCD process is the ability to synthesize alloyed catalysts in a single deposition process. By understanding the parametric effects of temperature and pressure on the deposition process with respect to particle size and distribution, we can optimize the PMCVD process to develop highly active catalysts that can be used in alkaline hydrogen systems.

[1] Durst, J. et al. New insights into the electrochemical hydrogen oxidation and evolution reaction mechanism. Energ. Environ. Sci. 7, 2255–2260 (2014).

[2]Sheng, W. et al. Hydrogen Oxidation and Evolution Reaction Kinetics on Platinum: Acid vs Alkaline Electrolytes. . Electrochem. Soc. 2010 volume 157, issue 11, B1529-B1536

[3] Garcia, Vargas, et al. “Chemical Vapor Deposition of Iridium, platinum, Rhodium, and Palladium.” Materials Transactions, Vol. 44, No. 9 (2003) pp. 1717-1728

[4] Serp, Philppe, et. al. “Chemical Vapor Deposition Methods for the Controlled Preparation of Supported Catalytic Materials.” Chem. Rev. 2002, 102, 3085−3128

[5] Papandrew, A. et al. Advanced Electrodes for Solid Acid Fuel Cells by Platinum Deposition on CsH2PO4. Chem. Mater. 2011, 23, 7, 1659-1667