Effects of pretreatments on the structure of palladium-containing amorphous alloys followed by DSC

Amorphous PdZr, PdCuZr and PdCuSi alloy ribbons and powders are characterized by DSC, XRD and XPS in the as-received state and after treatments with oxygen, hydrogen or dilute hydrogen fluoride solution. Zr-containing alloys are shown to undergo substantial structural changes resulting in palladium enrichment on their surface, whereas no apparent changes in the bulk structure are found for PdCuSi. catalytic activity and selectivity of the pretreated samples were tested in the hydrogenation of phenylacetylene.