Polymer electrolyte fuel cells (PEFC) are quantum reaction devices!

Polymer electrolyte fuel cells (PEFC) are quantum reaction devices!

Mar 1, 2013

Under the leadership of KASAI Hideaki , Professor, Graduate School of Engineering, Osaka University,  a group of researchers clarified that all reactions in polymer electrolyte fuel cells (PEFC) were quantum reactions by applying “quantum dynamics theory (Kasai Theory)” and “first principles calculation for quantum, Hyper-Naniwa.”  Polymer electrolyte fuel cells (PEFC) are expected to become the ultimate eco-friendly fuel cell. This group also succeeded in establishing an intelligent method for designing the PEFC through the use of FC-CMD (Computational Materials Design for Fuel Cell).

Clean fuel cells as an alternative to fossil fuels are being promoted as a technology for solving environmental and energy problems facing the world. The spread of PEFCs is widely expected once the practical application of PEFCs as fuel cells for automobiles and an energy source for homes has been perfected. PEFCs consist of a fuel electrode, a solid polymer membrane, and an air electrode. However, the mechanisms for reactions at the fuel electrode, the solid polymer membrane, and the air electrode as well as the design of the fuel cells had not been established previously.

However, this group has clarified that quantum tunnel effects contribute to the reaction mechanism in the fuel cells which were the state-of-the-art quantum reaction devices. The group also clarified the necessity to consider not only quantum effects of hydrogen whose mass was very small and shows outstanding quantum effects but also those of oxygen. The development of fuel cells by making use of these effects will lead to the realization of ultimate eco-friendly cells with high performance and low cost, contributing the realization of an energy-saving and low-carbon society.

Abstract

Dominance of quantum effects for the reactions in electrode and membrane of polymer electrolyte fuel cell (PEFC)

In this study, we employed “quantum dynamics theory (Kasai Theory)” and “first principles quantum dynamics calculation (Hyper-Naniwa)” to understand the reactions happening in the electrode and membrane of PEFC. We built intellectual design technique “FC-CMD (Computational Materials Design for Fuel Cell)” to elucidate the quantum effects governing the reactions which is confirmed through the effectiveness of the intelligently designed materials. This is the first reported result on this particular research field.
Research Results 1) Mechanism of reaction in anode and the intelligently designed sample: We found that the dissociative adsorption of hydrogen molecules on metal surfaces involves quantum tunneling effect. As an example of intellectual design, we used metal surface (Aluminium, etc.) coated by platinum with a larger lattice constant than the pure platinum as an anode catalyst. Our result shows that the platinum-coated surface, having extensional strains, not only promotes dissociative adsorption of hydrogen molecules but also suppresses carbon monoxide poisoning.
Research Results 2) Mechanism of reaction in cathode and the intelligently designed sample: Similarly, we determined that quantum effects play significant role in the dissociative adsorption mechanism of oxygen molecules. We used Pt/Fe catalyst as cathode; in which, two atomic layers of platinum are deposited on Fe(001) surface. It was observed that the induced magnetization of the surface Pt atoms efficiently allow the dissociative adsorption of oxygen molecules.
Research Results 3) Mechanism of reaction in the polymer membrane: The mechanism of positive hydrogen ion motion from the platinum surface (anode) to the Nafion chain (membrane) involves quantum effects. We found that the interaction of positive hydrogen ion with H2O to form H3O+ in the Nafion chain is explained quantum mechanically.


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