No abstract

A series of LaNiO3 materials were synthesized by the EDTA–citrate complexing method, modifying different physicochemical conditions. The LaNiO3 samples were calcined between 600 and 800 °C and characterized by XRD, SEM, XPS, CO-TPD, TG, DT, and N2 adsorption. The results evidence that although all the samples presented the same crystal phase, LaNiO3 as expected, some microstructural and superficial features varied as a function of the calcination temperature. Then, LaNiO3 samples were tested as catalysts of the CO oxidation process, a reaction never thoroughly analyzed employing this material. The catalytic results showed that LaNiO3 samples calcined at temperatures of 600 and 700 °C reached complete CO conversions at ~240 °C, while the sample thermally treated at 800 °C only achieved a 100% of CO conversion at temperatures higher than 300 °C. DRIFTS and XRD were used for studying the reaction mechanism and the catalysts’ structural stability, respectively. Finally, the obtained results were compared with different Ni-containing materials used in the same catalytic process, establishing that LaNiO3 has adequate properties for the CO oxidation process.

This work presents a dense ceramic-carbonate membrane as a new kind of reactor, where CO oxidation and CO 2 permeation processes are subsequently produced. This kind of membrane reactors may be applied for hydrogen enrichment of syngas mixtures. In here, a composite (doped-ceria and perovskite) was synthesized, sintered, and infiltrated with molten carbonates, showing that the reactor is able to perform both processes: the CO oxidation at the membrane reactor surface and subsequent CO 2 permeation through the molten carbonate phase. Moreover, results evidenced that perovskite phase importantly improves the oxygen permeation from the sweep to feed side (inverse permeation), enhancing CO oxidation and CO 3 2− formation without releasing oxygen on the feed side. When oxidation-permeation test was evaluated on a synthetic syngas mixture (H 2 + CO), it was observed that this membrane reactor has an important selectivity for CO oxidation, over hydrogen oxidation, confirming the possible use of this kind of membrane reactors for hydrogen enrichment in different applications.

No abstract

New Y-doped SDC ceramic–carbonate dual-phase membranes were prepared, characterized and evaluated, presenting high CO2 perm-selective properties.