Ordered mesoporous Pt/Fe3O4–CeO2 heterostructure gel particles with enhanced catalytic performance for the reduction of 4‐nitrophenol

Abstract

The unique physicochemical properties of ordered mesoporous transition metal oxides have attracted more and more attention. The hydrolysis process of metal oxide precursors is difficult to control, and it is difficult to synthesize an ordered mesoporous transition metal oxide material using the conventional template method. Ordered mesoporous Pt/Fe3O4–CeO2 heterostructure gel materials with excellent catalytic properties were successfully prepared using aerogel technology and the chemical deposition method. The Pt/Fe3O4–CeO2 material was an n–n combined heterostructured semiconductor material which consisted of a magnetic Fe3O4 layer, a CeO2 core and Pt noble metal doped nanoparticles. A layer of Fe3O4 thin film was formed on the surface of ordered mesoporous Pt/CeO2 gel matrix material using the chemical deposition method. The intriguing heterostructural features could facilitate reactant diffusion and exposure of active sites which could enhance synergistic catalytic effects between the Pt nanoparticles and CeO2 nanoparticles. Compared with Pt/CeO2, the prepared Pt/Fe3O4–CeO2 showed enhanced catalytic activity in the reduction of 4‐nitrophenol at room temperature. The catalytic activity of the heterostructure catalysts was systematically investigated using 4‐nitrophenol reduction as a model reaction. The results showed that the Pt (0.1%)/Fe3O4–CeO2 sample exhibited the optimal catalytic performance toward catalytic reduction of 4‐nitrophenol to 4‐aminophenol. The study provided a method for the preparation of heterostructure nanocatalysts with high efficiency, which would be effective for application in various catalytic reactions.