Nanostructured Au/Ti bimetallic electrodes in selective anodic oxidation of carbohydrates

The anodic oxidation of species possessing potentially oxidisable functionalities has been studied on a non conventional electrode system based on a Ti substrate partially coated by electrodeposited Au nanoparticles. The results show that the electrocatalytic behaviour of the Au nanoparticles, in the frame of such a bimetallic system, is very different from that of pure Au. In particular, catalytic synergy between Au and Ti leads to the electro-oxidation of aldoses and aldehydes, while ketoses and monohydric alcohols result electrochemically inert. A different behaviour has been observed in the case of bulk Au surface: all the species under investigation undergo oxidation, so that no selectivity is activated. A correlation is found between the actual electroactivity and the nature of the functional group, when considered together with the chemical structure of the molecule.