catena-poly[di-μ(2)-chloro(1,10-phenanthroline)cadmium(II)]

The crystal structure of the 1/1 adduct of cadmium dichloride with 1,10-phenanthroline, [CdCl2(C12H8N2)](n), is based on an infinite chain of Cd2Cl2 parallelograms sharing their Cd corners. The chain propagates in a zigzag manner along the c axis of the monoclinic unit cell. The Cd atom and the phenanthroline molecule both lie on special positions of 2 symmetry

Promotion by strontium fluoride of neodymium oxide catalysis of the oxidative coupling of methane

Catalytic performance measurements showed that CH4 conversion and C-2 selectivity were higher over SrF2/Nd2O3 catalyst than over pure Nd2O3 for the oxidative coupling of methane (OCM). XRD indicated that there was some exchange of F- and O2-, leading to the formation of tetragonal and rhombohedral NdOF phases during the catalyst preparation. After a certain amount of SrF2 was added to Nd2O3, the increase in surface basicity and conductivity, as well as the role of F- on the dispersion of surface active sites, would be favourable to a decrease in the secondary deep oxidation of methyl radicals and C-2 hydrocarbons, giving improved C-2 selectivity. Since there is a certain correlation between methane conversion and C-2 selectivity for an oxygen-limited OChl reaction, methane conversion is also expected to increase with the increase in C-2 selectivity

In situ confocal microprobe Raman spectroscopy study of the oxygen species over cerium oxide

In situ confocal microprobe Raman spectroscopy results showed that O-2(2-), O-2(-) and O-2(delta-) (0 < delta < 1) adspecies formed on the O-2 pretreated cerium oxide sample when the temperature was below 423 K. At 1023 K, only CeO2 F-2g peak (at 449 cm(-1)) and O-2(-) species (at 1159 cm(-1))were observed on the surface. The reactivity of methane with the oxygen species was lower than that of ethane with the oxygen species

Correcting cross-media instrument metamerism for reflectance estimation in multispectral imaging

Author name used in this publication: John H. Xin2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Active site of praseodymium orthovanadate catalyst in oxidative dehydrogenation of propane

The pure phase of praseodymium orthovanadate (PrVO4) has been prepared by the citrate method. The active sire of PrVO4 was studied by ESR, NO-TPD, O-2-TPD and O-18(2)-isotope exchange methods. The results of ESR and NO-TPD confirmed the presence of V4+ in the catalyst. O-18(2)-isotope exchange was through a single exchange procedure. From the result of O-2 + TPD and the kinetic study of O-18(2)-isotope exchange, one can reach a conclusion that the V4+ species associated with oxygen vacancies are the site for O-2 activation. The adsorbed O-2 or O- are the active oxygen species in propane oxidative dehydrogenation

Synthesis of compact NaA zeolite membrane by microwave heating method

A continuous and dense NaA zeolite membrane was synthesized by microwave heating method while employing a multi-step seeding LTA zeolite with the average size of 120 tun. The gas H-2/N-2 mixture separating results indicated that the mixture selectivity increased with increasing of synthesis times. In addition, selectivity of the three-step synthesis was higher than the value(3.74) expected from Kundsen diffusion

The active sites of the reference phase of SmVO4 as catalyst for propane oxidative dehydrogenation

The active sites of samarium orthovanadate (SmVO4) were studied by means of ESR, NO-TPD and temperature programmed O-18(2)-isotope exchange (TPIE) methods. The results of ESR and NO-TPD confirm the presence of V4+ in the catalyst. The TPIE revealed that the O-18(2)-isotope exchange was carried out through a single exchange procedure. The V4+ species associated with oxygen vacancies are the sites for O-2 activation

In situ confocal microprobe Raman spectroscopic studies on defective La-based complex oxides

The adsorption of O-2 over defective La2O3-based OCM catalysts with anionic vacancies, and the reaction of surface oxygen species with CH4 were studied by means of in situ confocal microprobe Raman spectra. The partially reduced oxygen species O-2(-), O-2(2-), O-2(delta-)(0<delta<1) and even the lattice oxygen ion O2- can be detected on the surface of O-2-pretreated La2O3-based catalysts. At lower temperatures (< 573 K) it is peroxide species O-2(2-) or O- that is more essential for the coupling of methane, while at higher temperatures the superoxide O-2(-) and lattice oxygen species O2- are rather important. It is easier for fluoride-containing La2O3-based catalysts to induce the oxygen species with fewer negative charges and the basicity of the catalyst surface is weakened, so that the C-2 selectivity for OCM reaction is improved