Manchester scientists in drive for cleaner energy

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For the first time, scientists have mapped the movement of electrical charge through a material known as a metal organic framework or ‘MOF’, designed to host charge in future vehicle fuel cells which offer a greener alternative to traditional combustion engines. By using a combination of X-ray and neutron techniques, scientists now have a better understanding of the flow of charge in the material, and can begin to design more efficient fuel cells in pursuit of cleaner energy.

Fuel cells convert the chemical energy of a fuel into electricity by means of a chemical reaction, and there are a variety of fuel cells available, with polymer electrolyte membrane fuel cells currently used most widely. However, the performance of a fuel cell depends on the electrolyte, the porous material at the centre of the cell which controls the flow of charge - to boost its efficiency, scientists are developing smart membranes with new materials which produce more charge.

A team from The University of Manchester linked up with others, including the University of Nottingham, have mapped the atomic structure and workings of the metal organic framework using intense X-rays at the UK’s Diamond Light Source ‘super-microscope’. They then used neutrons to map the flow of charge, known as proton conduction, in the material for the first time. The results, published in the Journal of the American Chemical Society, found that the protons move freely within a sphere, rather than the more common ‘jump diffusion between sites’ mechanism. This new knowledge will enable the design of improved proton conducting materials by optimising the pathway that the protons take.