L‐Arginine‐Triggered Self‐Assembly of CeO2 Nanosheaths on Palladium Nanoparticles in Water

Abstract

AbstractPd@CeO2 core–shell nanostructures with a tunable Pd core size, shape, and nanostructure as well as a tunable CeO2 sheath thickness were obtained by a biomolecule‐assisted method. The synthetic process is simple and green, as it involves only the heating of a mixture of Ce(NO3)3, l‐arginine, and preformed Pd seeds in water without additives. Importantly, the synthesis is free of thiol groups and halide ions, thus providing a possible solution to the problem of secondary pollution by Pd nanoparticles in the sheath‐coating process. The Pd/CeO2 nanostructures can be composited well with γ‐Al2O3 to create a heterogeneous catalyst. In subsequent tests of catalytic NO reduction by CO, Pd@CeO2/Al2O3 samples based on Pd cubes (6, 10, and 18 nm), Pd octahedra (6 nm), and Pd cuboctahedra (9 nm) as well as a simply loaded Pd cube (6 nm)–CeO2/Al2O3 sample were used as catalysts to investigate the effects of the Pd core size and shape and the hybrid nanostructure on the catalytic performance.