Improved polyol synthesis of palladium nanorods: an efficient catalyst for the selective hydrogenation of maleic anhydride to succinic anhydride

A one-pot, one-step, simple and fast polyol process for the synthesis of palladium nanorods at a relatively lower temperatures without any seeds or inert gas protection is presented. As-prepared unsupported Pd nanorods were used as catalysts for the selective hydrogenation of maleic anhydride (MA) to succinic anhydride (SA) in liquid phase. With the addition of potassium bromide and poly(vinyl pyrrolidone) (PVP), the palladium nanorods with an average aspect ratio of seven are obtained. The experimental indicates that both PVP and KBr are necessary for the forming of palladium 1D nanostructures. A possible anisotropic growth mechanism of palladium nanorods is also discussed. The as-prepared Pd nanorods showed highly enhanced activity and selectivity for the hydrogenation of MA to SA, giving 99.7% selectivity at 100% conversion, both of which are better than the data reported in other literature. Reusability tests of the prepared Pd nanorods also exhibit remarkable stability.