Characterization of Au3+ species in Au/C catalysts for the hydrochlorination reaction of acetylene

A set of Au/C catalysts for the gas phase hydrochlorination of acetylene to vinyl chloride monomer were prepared using a range of strong acids as impregnating solvents and varying the preparation drying temperature. The most active catalyst is the material prepared using aqua regia as solvent with an intermediate drying temperature of 140 °C. The effects of the catalyst preparation parameters on the catalytic activity are examined using XPS and TPR as analytical tools. In particular, the use of thermal reduction methods allows the determination of kinetic parameters for the reduction of Au3+ to Au0 by means of H2. These data support the existence of a redox cycle between Au3+/Au0 when carbon is used as support

Molybdenum blue nano-rings: an effective catalyst for the partial oxidation of cyclohexane

Molybdenum blue (MB), a multivalent molybdenum oxide with a nano-ring morphology is well-known in analytical chemistry but, to date it has been largely ignored in other applications. In the present work, MB has been characterized by STEM-HAADF imaging for the first time, showing the nano-ring morphology of this complex molybdenum oxide and the ordered super-molecular framework crystals that can result from the self-assembly of these MB nano-ring units. The potential of MB as an oxidation catalyst has also been investigated, where it is shown to have excellent catalytic activity and stability in the selective oxidation of cyclohexane to cyclohexanol and cyclohexanone which are important intermediates in the production of nylon

Supermassive Binaries and Extragalactic Jets

Some quasars show Doppler shifted broad emission line peaks. I give new statistics of the occurrence of these peaks and show that, while the most spectacular cases are in quasars with strong radio jets inclined to the line of sight, they are also almost as common in radio-quiet quasars. Theories of the origin of the peaks are reviewed and it is argued that the displaced peaks are most likely produced by the supermassive binary model. The separations of the peaks in the 3C 390.3-type objects are consistent with orientation-dependent "unified models" of quasar activity. If the supermassive binary model is correct, all members of "the jet set" (astrophysical objects showing jets) could be binaries.Comment: 31 pages, PostScript, missing figure is in ApJ 464, L105 (see http://www.aas.org/ApJ/v464n2/5736/5736.html

The Earlier the Better? Individual Participant Data and Traditional Meta-analysis of Age Effects of Parenting Interventions

Strong arguments have been made for early intervention for child problems, stating that early is more effective than later, as the brain is more malleable, and costs are lower. However, there is scant evidence from trials to support this hypothesis, which we therefore tested in two well?powered, state?of?the?art meta?analyses with complementary strengths: (a) Individual participant data (IPD) meta?analysis of European trials of Incredible Years parenting intervention (k = 13, n = 1696; age = 2–11); (b) Larger, trial?level robust variance estimation meta?analysis of a wider range of parenting programs (k = 156, n = 13,378, Mage = 2–10) for reducing disruptive behavior. Both analyses found no evidence that intervention earlier in childhood was more effective; programs targeted at a narrower age range were no more effective than general ones