Enhanced Catalytic Hydrogenation Activity and Selectivity of Pt-MxOy/Al2O3 (M = Ni, Fe, Co) Heteroaggregate Catalysts by in Situ Transformation of PtM Alloy Nanoparticles

PtM (M = Ni, Fe, Co) alloy nanoparticles were synthesized by a liquid phase reduction method employing butyllithium as a reducing agent. The alumina-supported PtM materials were then used as precursors to obtain the Pt-MxOy/Al2O3 catalysts through calcination. The influence of synthesis conditions of PtM alloy nanoparticles and the catalytic performance of the Pt-MxOy/Al2O3 catalysts for p-chloronitrobenzene hydrogenation reaction were investigated. The relevant characterizations such as XRD, XPS, and TEM were conducted for PtM alloy nanoparticles and Pt-MxOy/Al2O3 catalysts, and the result showed that the PtM nanoparticles are uniform alloy. Moreover, compared to PtM alloy nanoparticles, the Pt particle size of Pt-MxOy/Al2O3 using PtM alloy nanoparticle precursors did not increase by calcination, indicating good thermal stability. The catalytic activities of Pt-MxOy/Al2O3 for p-chloronitrobenzene hydrogenation reaction were significantly higher than that of control Pt/Al2O3 catalysts due to its strong Pt-MxOy interaction.