Vitamin E assisted polymer electrolyte fuel cells

Due to breathing O-2 from the air, vertebrates can suffer from diseases originating from oxidative stress. These, however, can be relieved by various antioxidants. Similarly, proton exchange membrane fuel cells (PEMFCs) suffer from the major problem of limited lifetimes, caused by chemical attacks by reactive oxygen species (ROS). Inspired by vertebrates, we herein show that the incorporation of a natural antioxidant, alpha-tocopherol (alpha-TOH), the most abundant component of vitamin E, which acts as a free radical scavenger, enables a maintenance of performance for PEMFCs which is impossible to achieve for fuel cells in the absence of alpha-TOH. It is notable that oxidized alpha-TOH can in turn be reduced by permeated H-2 during fuel cell operation, resulting in its regeneration. Such reversibility leads to a chemical circulation system, which not only ensures the effective recycling of alpha-TOH, but also permits efficient protection of proton exchange membranes (PEMs) and thus allows their long-term operation.