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Abstract: The high temperature vanadium pentoxide phase, β′-Li x V2O5, was synthesized via a new chemical synthesis involving the evolution of vanadium oxides from the 600°C heat treatment of the pure LiVS2 in air. By employing this method of synthesis, well-crystallized, rod-shaped β′-Li x V2O5 particles 20–30μm in length and 3–6μm in width were obtained. Moreover, the surface of β′-Li x V2O5 particles was found to be coated by an amorphous vanadium oxysulfide film (∼20nm in thickness). In contrast to a low temperature vanadium pentoxide phase (Li x V2O5), the electrochemical intercalation of lithium into the β′-Li x V2O5 was fully reversible where 0.0< x <2.0, and it delivered a capacity of 310mAhg−1 at a current rate of 0.07C between 1.5V and 4V. Good capacity retention of more than 88% was also observed after 50 cycles even at a higher current rate of 2C. [Copyright &y& Elsevier]

Abstract: The preferential oxidation of CO in a hydrogen-rich stream (PROX) at around room temperature was used to test the storage effect on catalytic activity of Au/TiO2. It is demonstrated in this study that indoor light is the main cause of the deactivation of the catalyst. UV–vis results suggest that the gold ions on the Au/TiO2 surface can be slowly reduced to gold metal during exposure to light; moreover, XPS detected a substantial drop in gold content on the TiO2 surface. However, Raman spectra reveal that the presence of nano-gold on the surface can weaken absorption from the anatase phase of TiO2, and exposure to the light during storage can further weaken absorption. Nevertheless, HRTEM has shown no apparent growth of gold particles on TiO2 under light. This study reveals that storing Au/TiO2 in a well defined dark environment under ambient conditions for as long as 5months ensures that its catalytic activity in PROX remains that of the fresh sample. [Copyright &y& Elsevier]