HER/HOR Catalysts for the H 2 -Br 2 Fuel Cell System

Abstract

Large scale deployment of renewable power sources like wind and solar require energy storage because of their intermittent nature. The Hydrogen-Bromine (H 2 -Br 2 ) fuel cell system is considered to be a suitable electrical energy storage system because of its high energy capacity, high round-trip conversion efficiency and low cost. While no precious metals are needed to catalyze the bromine reactions, the hydrogen (HER/HOR) reactions require a catalyst that is highly active, to keep the performance high and the cost low, and stable and durable in the highly corrosive HBr/Br 2 environment of the cell as required by the extended life of this application. Platinum, while having very high catalytic activity for the HER/HOR reactions, is not stable in the HBr/Br 2 environment. An alternative catalyst is needed. This paper discusses the performance and stability of various HER/HOR catalysts that we have evaluated for this fuel cell system.