Development of Germanium Oxide Media for the Production of Concentrated Hydrogen by the Steam-Iron Process

Some germanium oxide media were found to convert dilute H2 to concentrated H2 more effectively than the iron oxide medium used for the present steam-iron process. Although the yield of concentrated H2 for unsupported GeO₂ media was lower than that for the iron oxide medium, GeO₂/Al₂O₃ media exhibited higher yields of concentrated H₂. The addition of third components such as Ni and Cu to GeO₂/Al₃O₃ further Increased the yield and enhanced the stability of the medium. It was also found that dilute CO gas was converted to concentrated H₂ by using germanium oxide media. Although the GeO₂/Al₂O₃ medium did not exhibit a high yield of concentrated H₂ from the dilute CO gas, the addition of third components (e.g., Ni and Cu) markedly enhanced the yield. The yield of concentrated H₂ for the germanium oxide media was not decreased by the addition of H2S to the dilute H₂ gas, while that for the iron oxide was lowered slightly. From the results of X-ray diffraction of the media, a role of the third component was also discussed.