RuO2 Nanorods as an Electrocatalyst for Proton Exchange Membrane Water Electrolysis

摘要

The desire for pure diatomic hydrogen gas, H2(g), has been on the rise since the concept of the hydrogen economy system was proposed back in 1970. The production of hydrogen has been extensively examined over 40 + years as the need to replace current fuel sources, hydrocarbons, has become more prevalent. Currently there are only two practical and renewable production methods of hydrogen; landfill gas and power to gas. This study focuses on the later method; using various renewable energy sources, such as photovoltaics, to provide off-peak energy to perform water electrolysis. Efficient electrolysis takes place in electrochemical cells which maximize performance efficiency with the use of noble metal electrocatalyst. Optimizing these electrocatalyst to be less material dependent, highly durable, and more efficient will support the implementation of power to gas electrolysis into the energy infrastructure.The main focus of this study is to explore RuO2 nanorods as a possible electrocatalyst for Proton Exchange Membrane (PEM) water electrolysis. A PEM electrolyzer cell has been constructed and fitted with a RuO2 nanorod decorated, mixed metal oxide (MMO) ribbon mesh anode catalyst structure. The current density-voltage characteristics were measured for the RuO2 nanorod electrocatalyst while under water feed operation. The electrocatalytic behavior was compared to that of ribbon mesh anode catalyst structures not decorated with RuO2 nanorods; one coated with a Ir/Ta MMO catalyst, the other was stripped of the MMO coating resulting in a Ti ribbon mesh anode. The results of these experiments show increased activity with the RuO2 nanorod electrocatalyst corresponding to a decrease in electrochemical overpotential. Through the collection of experimental data from various electrolyzer cell configurations, these overpotenials were able to be identified, resulting in categorical attributions of the enhanced catalytic behavior examined.