The formation of oxygen vacancies in nanoparticles Ce(n)O(2n) (n < or = 80), studied using density-functional calculations, is found to be greatly facilitated compared to extended surfaces, which explains the observed spectacular reactivity of nanostructured ceria.

Abstract Cerium dioxide CeO 2 (ceria) is an important material in catalysis and energy applications. The intrinsic Frenkel Schottky defects can impact a wide range of properties including the oxygen storage capacity, redox cycle, ionic thermal transport. Here, we study on structural dynamics ceria using density functional theory. phonon contributions to free are found reduce defect formation en...

The attention on CeO2-NPs environmental and in vivo effects is due to their presence in diesel exhaust and in diesel filters that release a more water-soluble form of ceria NPs, as well as to their use for medical applications. In this work, acute and subacute in vivo toxicity assays demonstrate no lethal effect of these NPs. Anyhow, performing in vivo evaluations on CD-1 mouse systems, we demo...

Low-temperature scanning tunneling microscopy and spectroscopy have been employed to analyze the local electronic structure of the (111) surface of a ceria thin film grown on Ru(0001). On pristine, defect-free oxide terraces, the empty 4f states of Ce(4+) ions appear as the only spectral feature inside the 6 eV oxide band gap. In contrast, occupied states are detected between -1.0 and -1.5 eV b...

Ceria-supported Pd is a promising heterogeneous catalyst for CO oxidation relevant to environmental cleanup reactions. Pd loaded onto a nanorod form of ceria exposing predominantly (111) facets is already active at 50 °C. Here we report a combination of CO-FTIR spectroscopy and theoretical calculations that allows assigning different forms of Pd on the CeO2(111) surface during reaction conditio...

In this paper we develop an analytical framework for the study of electrochemical impedance of mixed ionic and electronic conductors (MIEC). The framework is based on non-equilibrium thermodynamics and it features the coupling of electrochemical reactions, surface transport and bulk transport processes. We utilize this work to analyze two-dimensional systems relevant for fuel cell science via t...

Particulate matter and NO x emissions from diesel exhaust remains one of the most pressing environmental problems. We explore the use of hierarchically ordered mixed Fe-Ce-Zr oxides for the simultaneous capture and oxidation of soot and reduction of NO x by ammonia in a single step. The optimized material can effectively trap the model soot particles in its open macroporous structure and oxidiz...

Single-atom catalysts maximize the utilization of supported precious metals by exposing every single metal atom to reactants. To avoid sintering and deactivation at realistic reaction conditions, single metal atoms are stabilized by specific adsorption sites on catalyst substrates. Here we show by combining photoelectron spectroscopy, scanning tunnelling microscopy and density functional theory...

Nanoscale solely amorphous layer is achieved in silicon (Si) wafers, using a developed diamond wheel with ceria, which is confirmed by high resolution transmission electron microscopy (HRTEM). This is different from previous reports of ultraprecision grinding, nanoindentation and nanoscratch, in which an amorphous layer at the top, followed by a crystalline damaged layer beneath. The thicknesse...

The species formed by exposure of a Pd/ceria catalyst to SO2 under various conditions have been studied using temperature-programmed desorption (TPD) and FTIR. For adsorption of SO2 between 298 and 473 K, a molecular SO2 species adsorbs on the surface, possibly as a surface sulfite; and this species converts to a sulfate above 473 K. Exposure of Pd/ceria to SO2 at temperatures above 473 K in th...