Polybetaine-stabilized palladium-containing nanoparticles, method for preparing the particles, and catalyst prepared from the particles to produce vinyl acetate

摘要

Soluble nanoparticles (I) that contain palladium optionally with Group Ib and VIIIb metals are embedded in a protective colloid that contains a polymer having betaine groups. Also claimed are: (i) a process for the production of (I) by reaction of a palladium compound, optionally with Group Ib and VIIIb metal compounds with a reducing agent in water or a solvent whereby the reduction is carried out in the presence of a protective colloid that contains a polymer, the side chains of which contain betaine groups or the protective colloid is converted to the resulting sol after the reduction step; (ii) the resulting sol whereby the electrolyte contains chloride, bromide or iodide; and (iii) a catalyst for the production of vinyl acetate whereby a sol of the nanoparticles (I) is applied to a catalyst support by dipping, spraying, immersion, impregnation, spray drying or spin coating.