A novel, high temperature solid absorbent based on lithium orthosilicate (Li(4)SiO(4)) has shown promise for postcombustion CO(2) capture. Previous studies utilizing a clean, synthetic flue gas have shown that the absorbent has a high CO(2) capacity, >25 wt %, along with high absorption rates, lower heat of absorption and lower regeneration temperature than other solids such as calcium oxide. The current effort was aimed at evaluating the Li(4)SiO(4) based absorbent in the presence of contaminants found in typical flue gas, specifically SO(2), by cyclic exposure to gas mixtures containing CO(2), H(2)O (up to 25 vol. %), and SO(2) (up to 0.95 vol. %). In the absence of SO(2), a stable CO(2) capacity of ∼ 25 wt % over 25 cycles at 550 °C was achieved. The presence of SO(2), even at concentrations as low as 0.002 vol. %, resulted in an irreversible reaction with the absorbent and a decrease in CO(2) capacity. Analysis of SO(2)-exposed samples revealed that the absorbent reacted chemically and irreversibly with SO(2) at 550 °C forming Li(2)SO(4). Thus, industrial application would require desulfurization of flue gas prior to contacting the absorbent. Reactivity with SO(2) is not unique to the lithium orthosilicate material, so similar steps would be required for other absorbents that chemically react with SO(2).

Transition metal (Co, Fe, Mn)‐doped In2O3−y mesoporous oxides are synthesized by nanocasting using mesoporous silica as hard templates. 3D ordered mesoporous replicas are obtained after silica removal in the case of the In‐Co and In‐Fe oxide powders. During the conversion of metal nitrates into the target mixed oxides, Co, Fe, and Mn ions enter the lattice of the In2O3 bixbyite phase via isovalent or heterovalent cation substitution, leading to a reduction in the cell parameter. In turn, non‐negligible amounts of oxygen vacancies are also present, as evidenced from Rietveld refinements of the X‐ray diffraction patterns. In addition to (In1−xTMx)2O3−y, minor amounts of Co3O4, α‐Fe2O3, and MnxOy phases are also detected, which originate from the remaining TM cations not forming part of the bixbyite lattice. The resulting TM‐doped In2O3−y mesoporous materials show a ferromagnetic response at room temperature, superimposed on a paramagnetic background. Conversely, undoped In2O3−y exhibits a mixed diamagnetic‐ferromagnetic behavior with much smaller magnetization. The influence of the oxygen vacancies and the doping elements on the magnetic properties of these materials is discussed. Due to their 3D mesostructural geometrical arrangement and their room‐temperature ferromagnetic behavior, mesoporous oxide‐diluted magnetic semiconductors may become smart materials for the implementation of advanced components in spintronic nanodevices.

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Cell viability and release ion concentration of two newly developed Fe-based alloys.