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Abstract
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The influence of titanium and vanadium on the hydrogen transport rate through thin amorphous alumina
films is addressed. Only small changes in the transport rate are observed when the Al2O3 are covered
with titanium or vanadium. This is in stark contrast to results with a Pd overlayer, which enhances the
transport by an order of magnitude. Similarly, when titanium is embedded into the alumina the transport
rate is faster than for the covered case but still slower than the undoped reference. Embedding vanadium
in the alumina does not yield an increase in uptake rate compared to the vanadium covered oxide layers.
These results add to the understanding of the hydrogen uptake of oxidized metals, especially the alanates,
where the addition of titanium has been found to significantly enhance the rate of hydrogen uptake. The
current findings eliminate two possible routes for the catalysis of alanates by Ti, namely dissociation and
effective diffusion short-cuts formed by Ti. Finally, no photocatalytic enhancement was noticed on the
titanium covered samples.
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