少量の貴金属を含む銅－ジルコニウム金属ガラスを用いた高活性メタノール水蒸気改質触媒の調製

摘要

メタノールの水蒸気改質反応（以下，改質反応）は，燃料電 池用高純度水素の製造法の一つとして注目されている．改質 反応用触媒の開発については，Ⅶ族元素あるいは鋼銅を 中心にして多くの成果が報告されている．%Methanol steam reforming has been carried out over catalysts prepared from glassy alloy containing a small amount of noble metals. When the alloy is treated at a temperature above the crystallization temperature, the reforming activity increases, whereas the original alloy does not have the similar activity. The reforming activity of the treated alloys increases with the decreasing content of noble metals down to 1 at%. The DSC (differential scanning calorimetry) analysis of the original alloy has revealed that the activity is related to the extent of supercooling and endothermic heat observed between the glassy temperature and crystallization temperature. Furthermore, the copper particle size of the treated alloy is related to the range of supercooling. These results indicate that the noble atoms are uniformly dispersed into the glassy Cu-Zr alloy by heating from the glass transition temperature to crystallization temperature. When the Cu-Zr alloy with a small amount of noble metals is oxidized over the crystallization temperature, the alloy changes to fine copper particles supported on zirconium oxide. A highly active reforming catalyst can be prepared from a glassy Cu-Zr alloy containing a small amount of noble metals.