Palladium supported on amino functionalized magnetic MCM-41 for catalytic hydrogenation of aqueous bromate

Abstract

Pd supported on amino functionalized magnetic MCM-41 was synthesized by deposition–precipitation (DP) and impregnation (IMP) methods. The catalysts were characterized by N₂ adsorption, XRD, FTIR, CO chemisorption, TEM, XPS and VSM. Liquid phase catalytic hydrogenation of bromate was tested over these catalysts. The results showed that the DP catalyst had a higher activity than the IMP catalyst, due to its higher Pd dispersion. With regards to DP catalysts supported on magnetic MCM-41 with different NH₂ loading amounts, a positive relationship was observed between the Pd dispersion and the initial catalytic activity. Moreover, the DP-2 catalyst (supported on magnetic MCM-41 with 0.99 mmol of NH₂ per g) was completely recovered with an external magnetic field, and the catalytic activity remained unaltered even after 5 repeated cycles for the bromate reduction.