Resnick Institute

2015 Resonate Award Winners

Tsutomu Ioroi

Resonate Award recipient for innovating enhanced materials for next-generation fuel cells.

The Challenge

Fuel cells produce electricity through an electrochemical process and do not generate particulate pollutants, unburned hydrocarbons, or the gases that produce acid rain. They emit less carbon dioxide than other less efficient technologies, and their use with renewable fuels can make them carbon neutral. Degradation of the electrocatalyst in polymer electrolyte fuel cells (PEFC), that use hydrogen as their fuel source, contributes to significant losses in performance over time. This adds considerable expense making their adoption prohibitive. Improving performance and durability of these systems is a fundamental challenge that Dr. Ioroi has addressed via materials innovations.

The Response

Dr. Ioroi developed a stable catalyst material for PEFCs from oxygen-deficient titanium oxides, called “Magneli phase” titanium oxides. He demonstrated that Magneli phases exhibit better stability against corrosion while retaining high electronic conductivity needed for electrode materials compared to conventional carbon supported platinum electrodes in PEFCs. Dr. Ioroi has also contributed to the enhancement in the total efficiencies of a unitized regenerative fuel cell (URFC). A URFC combines the functions of a fuel cell with that of a water electrolyzer: the water electrolyzer splits water into H2 and O2 using electricity and the fuel cell consumes the H2 and 02 to produce electricity. By identifying materials and structures that are more active during both the fuel cell and water splitting reactions, he has helped to improve the round trip efficiencies of these devices.

The Future

Making fuel cell systems more durable and efficient is an important strategy aimed at reducing costs, which should increase adoption of this promising technology. Ioroi’s PEFC breakthrough technology has received global attention and financial support from NEDO, fuel cell system developers. Additionally, his URFC work has given rise to a growing trend in their development.