A detailed investigation has been carried out into the effect of annealing RuO, xH,O at different temperatures on its ability to mediate the oxidation of water, and its stability towards anodic corrosion. The percentage corrosion of the heated samples when exposed to a strong oxidant such as CeIV ions decreased with increasing annealing temperature, and at temperatures >/ 140 "C no corrosion was observed, only 0,-catalytic activity. This effect was associated with a decrease in percentage H,O content of the samples owing to a reduction in the number of defect sites present. Raising the annealing temperature of the powders from 140 to 900 "C caused a concomitant drop in catalytic activity as a result of an observed decrease in crystallite size and surface area available for catalysis measured by X-ray diffraction and transmission electron microscopy-techniques. Thus an annealing temperature of 140-150 "C for the RuO;xH,O samples represented an optimum for catalytic activity where corrosion was absent. When this material was used to catalyse the oxidation of water by CerV ions, it retained its activity after repeated use and was able to generate an amount of 0, which was 16 times larger than that of the catalyst (in molar terms). In addition, this catalyst was found to mediate the oxidation of water by many other strong oxidants such as BrO;, MnO;, IO;, PbO, and MnO, (activated).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.