Hyrdogen bronzes from VMoO5.5 : An X-ray diffraction investigation

Hydrogen bronzes obtained by spillover of hydrogen onto Pt particles deposited on the surface of VMoO_5.5 have been examined by X-ray diffraction. The results show that H_3.4VMoO_5.5 is crystalline and that no intermediate crystalline phase is formed during the insertion of hydrogen in the host lattice. Oxidation of the bronze restores the initial oxide phase. Upon back-titration with H₂ at 60°C, the bronze phase reappears (indicating the reversible character of these bronzes) at a much higher rate than when the bronze is formed for the first time.