Solid state NMR for dynamics and kinetics of hydrogen uptake and transport in novel bionanomaterials for energy applications ('Nano-NMR')

Lead Research Organisation: University of Warwick
Department Name: Physics


The Stern report stresses that we must move rapidly to the use of sustainable energy. The move into the hydrogen economy is still 10-20 years away. This is desperately limited by four major issues: (i) current fuel cells that use hydrogen require precious metal electrodes which are very expensive and the catalyst life, and high expense, limit fuel cell economics; (ii) better hydrogen stores are needed to obtain the 7% H by mass needed for commercial viability (metal hydride based stores are simply too heavy); (iii) not only the H mass in the store, but also the kinetics of H uptake and release are vitally important; (iv) we do not yet have the technology to measure and follow the speciation and transport of hydrogen within solid matrices or, indeed, the capability to understand what is happening within the structure of the material as it interacts with hydrogen. This feasibility study brings together world class expertise across 2 universities that are developing closer research collaborations to address these problems (prior to maturation of a full grant proposal following this one) within an extant framework of academic and industrial collaboration, embedded within within two major investments: by the DTI (6.3m for infrastructure) and by EPSRC (1.5m for H-supply chain research using extant materials). This feasibility study, and its follow-up full project, will sit within this framework, against a raft of ~ 20 collaborating companies, the whole programme being managed by a full time project manager currently in post, funded by University of Birmingham. Within the feasibility study we will use a completely novel method: bacterial biomanufacturing of precious metal nanomaterials, bottom up, atom by atom, with runaway crystal growth and nanoparticle agglomeration (which limits commercial synthesis) controlled by the scaffolding function of the bacterial cell surface. Such bionanomaterials are suggested (April 07 Biotechnol Letts) to be potentially superior to commercial fuel cell catalysts; they are comparably active (Bio-Pt) or have totally unexpected activity (Bio-Pd) and biomanufacturing is highly scaleable to kilo/tonnage-scale. Pd/Au bionanohybrids are recently shown; this is current 'state of the art' in fuel cells where Au(0) is incorporated into bimetallics to oxidise poisonous CO in situ. We will construct and test PEM fuel cells with biometals and bio-bimetallic hybrids, asking WHY these are so active (versus commercial materials) using as tools EPR, SQUID, XRD, FTIR and synchrotron methods, as well as solid-sate NMR (1H and 2H) to follow specifically hydrogen transport and speciation within the metallic lattices. We will also start to develop solid state NMR of ther palladium nucleus itself, to gain novel insight into the Pd-H 'dialogue' at the grain boundaries/dislocations in situ which has beenbeyond reach until now by the lack of methodology. The problem of hydrogen stores will be tackled by adopting potential lightweight carbon storage materials (activated carbon particles and milled graphite; they have poor H-kinetics), overlaying these with a palladium thin film. Pd(0), uniquely, dissociates H2 and moves hydrogen around as highly reactive free H-atoms. We will use the ability of bacteria to colonise and swim over all surfaces, even occluded nooks and crannies. The bacteria will then be palladised and dried to leave a nano-Pd(0)-all-over-film. This will combine the excellent H-transfer and H-conduction properties of Pd(0) (only a few atoms thick is needed) with the ability to bio-direct a Pd-film (controlled size/distribution) which contrbutes little to the overall weight. Transfer of H atoms into the Pd(0)/across the Pd/C boundary layer and into the carbon, will be followed using solid state 1H and 2H NMR to follow the 'dialogue' between the two materials, and ascertain what is happening (and how fast) as the H delivered by the Pd(0) as individual atoms, goes into the carbon matrix for storage.


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