Core-Shell Fe2O3@La1−xSrxFeO3−δ Material for Catalytic Oxidations: Coverage of Iron Oxide Core, Oxygen Storage Capacity and Reactivity of Surface Oxygens

A series of Fe2O3@LSF (La0.8Sr0.2FeO3−δ perovskite) core-shell materials (CSM) was prepared by infiltration of LSF precursors gel containing various complexants and their mixtures to nanocrystalline aggregates of hematite followed by thermal treatment. The content of LSF phase and amount of carboxyl groups in complexant determine the percent coverage of iron oxide core with the LSF shell. The most conformal coating core-shell material was prepared with citric acid as the complexant, contained 60 wt% LSF with 98% core coverage. The morphology of the CSM was studied by HRTEM-EELS combined with SEM-FIB for particles cross-sections. The reactivity of surface oxygen species and their amounts were determined by H2-TPR, TGA-DTG, the oxidation state of surface oxygen ions by XPS. It was found that at complete core coverage with perovskite shell, the distribution of surface oxygen species according to redox reactivity in CSM resemble pure LSF, but its lattice oxygen storage capacity is 2–2.5 times higher. At partial coverage, the distribution of surface oxygen species according to redox reactivity resembles that in iron oxide.

Highly Stable 1,2-Dicarbonyl Radical Cations Derived from N-Heterocyclic Carbenes

<div>The present manuscript describes the design, synthesis, and characterization of the most stable organic radical reported up to date.</div><div><br></div><div>Here we report:</div><div>▪ Synthesis and full characterization including X-ray structure of stable 1,2-dicarbonyl radicals</div><div>▪ Proposed mechanism for the formation of the presented radicals</div><div>▪ Redox reactivity of the radicals</div><div>▪ Stability of the radicals under various organic and inorganic conditions</div><div><u></u></div>

Solvothermal and mechanochemical intercalation of Cu into La2O2S2 enabled by the redox reactivity of (S2)2- pairs

Intercalation of Cu into layered polychalcogenide La2O2S2 was demonstrated to be viable both in solvothermal condition at 200 °C and mechanical ball milling at ambient temperature. This result evidences the...