Phase composition, morphology, properties and improved catalytic activity of hydrothermally-derived manganese-doped ceria nanoparticles. (7th January 2022)

• Record Type: Journal Article
• Authors: Kurajica, S; Ivković, I K; Dražić, G; Shvalya, V; Duplančić, M; Matijašić, G; Cvelbar, U; Mužina, K
• Is Part Of: Nanotechnology. Volume 33:Number 13(2022)
• Publication Date: 2022-01-07
• Subjects: hydrothermal synthesis -- doped ceria -- manganese -- nanoparticles -- romanechite-like phase; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ac44ed
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: Manganese-doped ceria nanoparticles were prepared by hydrothermal synthesis and the prepared samples were thermally treated at 500 °C for 2 h. The samples were investigated using x-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive x-ray spectroscopy (EDS), N2 adsorption and x-ray photoelectron spectroscopy (XPS). XRD revealed that nanocrystalline ceria is the main phase in all samples, while a romanechite-like phase (Na2 Mn5 O10 ) appears in the sample doped with 30% of Mn. TEM coupled with EDS exposed the presence of the same phase in the sample doped with 20% Mn. While ceria particles have spherical morphology and particle size ranging from 4.3 to 9.2 nm, the rare crystals of the romanechite-like phase adopt a tubular morphology with a length of at least 1 μ m. However, the decrease in the ceria lattice constant and the EDS spectra of the ceria nanoparticles clearly indicate that a substantial amount of manganese entered the ceria crystal lattice. Manganese doping has a beneficial impact on the specific surface area of ceria. XPS measurements reveal a decrease in the Ce 3+ /Ce 3+ + Ce 4+ content in the doped samples which is replaced by Mn 3+ . Moreover, a drastic increase in adsorbed oxygen is observed in the doped samples which is the consequence of the increase in Mn 3+ species that promotes oxygen migrations to the surface of the sample. Compared to the pure sample, the doped samples showed significantly higher catalytic activity for the process of toluene oxidation.