Au/TiO2 catalysts were prepared by incipient wetness impregnation and tested for the room temperature photocatalytic reforming of methanol in aqueous solution to produce hydrogen. These catalysts proved to be active for this reaction, with the dependence on loading of gold showing a double maximum in yield at 0.2 and 2 weight % with a low rate below 0.01% and above 10%. A model is proposed for the reaction, involving band gap excitation of titania electrons to produce O -species which are then used to oxidise the methanol via adsorbed methoxy, which is formed by dehydrogenation on the metal component. The reaction is truly bi-functional and only takes place at the interface between the metal and the support.An ideal for the future well-being of the human population of the world (and for the biota as a whole) is to find an energy source which has the following properties: 1 It must be environmentally benign, producing minimal pollution of any kind, and taking up as little useful space as possible; 2 It must have usable energy density; 3 It should be usable on a local basis -strategically eliminating dependence upon external influences; 4 It should be economically viable, which is not as simple a point as might at first be imagined, since it involves future costs of materials and government subsidies which are currently in place for various energy sources (nuclear, for instance) and which will, in turn, relate closely to item 3;5 It needs to be technologically feasible and available. In many ways hydrogen best fits most of these points, except for 4. It fits 1, provided that it is part of a cycle, that is hydrogen is produced from water and is burned back to water to produce energy from the exothermic oxidation of hydrogen. 2 also applies, but only if the hydrogen is used at the source of production, or is transported in a densified form (for instance, as a liquid, a high pressure gas, or condensed into a microporous high surface area solid). The technology is currently available to achieve 3 and 5, though the technology certainly can be improved. 4 is the main problem, but as stated above, hydrogen may well become economically viable in the event of a big increase in the price of oil or big taxes on fossil fuels more generally, related to the pollution they cause and their strong connection to global warming. More importantly for the West, that part of the world is currently unrealistically dependent on oil supplies from unstable parts of the world. Any responsible Western state should be investing VERY heavily, right now, in alternative energy sources, one of these being renewable and minimally-polluting hydrogen production.The objective of this paper, then, is to describe one method of producing hydrogen, that is, by using photocatalysis, which has the potential to be used to split water using sunlight. However, the rates of this reaction are quite low and so the work described here focuses on the room temperature reforming of methanol, which does effectively split water. Previous work in this group [1]...
