Catalytic activity of Cu-based amorphous alloy ribbons modified by cathodic hydrogen charging

Abstract

Since hydrogen is known to be one of the most efficient embrittling atomic species, cathodic hydrogen charging was used in an attempt to modify the structure, composition, and morphology of Cu-based amorphous alloy ribbons. Various methods of analysis such as X-ray electron microanalysis, SEM, high resolution Auger microanalysis (SAM), with varying lateral resolution and different information depths, as well as measurements of specific surface area, porosity and catalytic tests, were used to follow the changes within the ribbons and at the surface, and their interrelations with catalytic activity. The activity in a test reaction (dehydrogenation of 2-propanol) was enhanced up to conversion levels of 66% for Cu–Ti and of 88% for Cu–Hf, which are much higher than those obtained with all other pre-treatments previously applied. The rather low specific surface area and porosity, as well as a lack of Cu 0 both before and after the catalytic test suggest that the generally accepted mechanism for the dehydrogenation of alcohols over copper catalysts with the involvement of Cu 0 is not operative here.