Photochemical Deposition of Highly Dispersed Pt Nanoparticles on Porous CeO2 Nanofibers for the Water‐Gas Shift Reaction

Abstract

Ceria (CeO2) nanofibers with high porosity are fabricated using an approach involving sol–gel, electrospinning, and calcination. Specifically, cerium(III) acetylacetonate and polyacrylonitrile (PAN) are dissolved in N,N‐dimethylformamide (DMF) and then electrospun into nanofibers. The PAN matrix plays a critical role in stabilizing the porous structure from collapse during calcination in air up to 800 °C. CeO2 porous nanofibers comprising an interconnected network of single crystalline and fully oxidized CeO2 nanoparticles about 40 nm in size are obtained. The hierarchically porous structure of the CeO2 nanofibers enables the facile deposition of Pt nanoparticles via heterogeneous nucleation in a photochemical method. When conducted in the presence of poly(vinyl pyrrolidone) (PVP) and 4‐benzyolbenzoic acid, uniform Pt nanoparticles with an average diameter of 1.7 nm are obtained, which are evenly dispersed across the entire surface of each CeO2 nanofiber. The high porosity of CeO2 nanofibers and the uniform distribution of Pt nanoparticles greatly improve the activity and stability of this catalytic system toward the water‐gas shift reaction. It is believed that this method could be extended to produce a variety of catalysts and systems sought for various industrial applications.