Propane oxidation was studied on a Pd-supported Al 2 O 3 catalyst promoted by ceria, when this ceria was first grafted as a monolayer over alumina. The reaction proceeded under different feed conditions, and the surface sites were identified by X-ray photoelectron spectroscopy (XPS) in a pretreatment chamber and then compared to temperature-programmed desorption, temperature-programmed surface reaction (TPSR), and catalytic results, in the presence and absence of water. Stable catalyst performance was achieved in experiments after 20 h with time on stream, to get reliable data for further interpretation. This observation is true for all reaction conditions, with reducing, stoichiometric, or excess oxygen content in the reaction feed. The Pd/CeO 2 /Al 2 O 3 catalyst is less active for oxidation at low temperatures but suddenly becomes very active at high temperatures. However, in the case of the latter, large quantities of H 2 were released, which suggests a drastic change in selectivity. TPSR results showed that the presence of CeO 2 affected the oxidation, inhibiting the reaction as well as the re-forming in the first domain. But the combination of both was beneficial in terms of higher H 2 production. XPS results showed that the catalysts containing CeO 2 form the highest oxidation state palladium species, probably PdO 2 (338 eV), after the oxidation of propane. From these results it is suggested that besides the Pd 0 /PdO interface, which are active sites for propane oxidation, the Pd 0 /PdO 2 sites also favor the selective oxidation toward re-forming.

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Among other taxa of Araceae, the genus Anthurium is the largest of the family and one of the most important taxa. Some species of this genus have been used as a condiment, and its plants as ornaments and medicines for over a century. Anthurium maricense is an endemic species from "restingas" of Rio de Janeiro, Brazil, and it is used as ornamental and medicinal plant. This paper aimed an anatomical and toxicological study of its vegetative organs. A. maricense has subterraneous rhizome, adventitious roots and complete leaves. The anatomical features of vegetative organs are similar to other species of Araceae and genus Anthurium, especially the velamen in roots and calcium oxalate crystals in all organs. Under scanning electron microscopy (SEM), longitudinal grooves were observed in the raphides. For toxicological analyses, whole (with crystals) and centrifuged (free from crystals) fractions of the juices of each organ were administered via mouthwash and plantar inoculation to groups of five mice. The formation of edema was observed at 1, 3, 6, 24 and 96 hours and 7, 14, 21 and 28 days. The oral inoculations presented negative results for all groups, without edema. The plantar inoculations showed differing results: with centrifuged juices, mild edema formed but regressed; with whole juices, some animals presented severe edema. Our results indicated distribution and morphology of raphides and diverse chemical substances were related to the edematogenic process. A. maricense may potentially induce more chronic edema if compared to other species of Araceae.