Water Electrolysis: H2/O2 Generation
With the commercialization and market penetration of fuel-cell-powered vehicles, the hydrogen economy is poised to grow and expand throughout the US and the world. Yet the production of hydrogen remains largely based on the conversion of fossils such as methane and coal. An alternative to the use of fossil fuels is the reduction of water molecules to hydrogen. Water splitting, or water electrolysis, is performed in a technology called an electrolyzer, where the anode and cathode are separated by a solid polymer electrolyte membrane. At the anode, oxygen molecules are evolved, while at the cathode, hydrogen molecules are evolved, and the membrane separator allows selective transport of either protons or hydroxyl anions. This type of device is similar to a fuel cell but operates in reverse; in a fuel cell, energy is produced when hydrogen (or another fuel) is oxidized (and water is produced) and electrons are captured, while in an electrolyzer energy is input to react water molecules and produce hydrogen and oxygen. In electrolyzers, the kinetics and overall efficiency is currently limited by the anode, where oxygen is evolved. Thus, better catalysts are needed to enable faster oxygen evolution; further, it is desirable for future devices to be designed to be free of precious metals in the catalyst. Thus, our research focuses on alkaline electrochemical systems, where catalysts comprised entirely of non-precious metals are stable and where the kinetics of oxygen evolution are potentially enhanced at high pH. Our catalyst research focuses on the synthesis and characterization of bimetallic and trimetallic nanoparticle catalysts for alkaline oxygen evolution, where we aim to create nanostructured catalysts with high mass activity and minimal mass transport limitations.
Award Number: 1738165
With collaborator Prof. Clemens Heske
Award Number: 1703827
With Collaborator Prof. Jingyi Chen