Highly Active and Selective Supported Rhenium Catalysts for Aerobic Oxidation of n-Hexane and n-Heptane

XAS investigation of silica aerogel supported cobalt rhenium catalysts for ammonia decomposition

The implementation of ammonia as a hydrogen vector relies on the development of active catalysts to release hydrogen on-demand at low temperatures. As an alternative to ruthenium-based catalysts, herein we report the high activity of silica aerogel supported cobalt rhenium catalysts. XANES/EXAFS studies undertaken at reaction conditions in the presence of the ammonia feed reveal that the cobalt and rhenium components of the catalyst which had been pre-reduced are initially re-oxidised prior to their subsequent reduction to metallic and bimetallic species before catalytic activity is observed. A synergistic effect is apparent in which this re-reduction step occurs at considerably lower temperatures than for the corresponding monometallic counterpart materials. The rate of hydrogen production via ammonia decomposition was determined to be 0.007 mol_H2 g_cat^-1 h^-1 at 450 °C. The current study indicates that reduced Co species are crucial for the development of catalytic activity.

Novel Methinic Functionalized and Dendritic C-Scorpionates

The study of chelating ligands is undoubtedly one of the most significant fields of research in chemistry. The present work is directed to the synthesis of new functionalized derivatives of tripodal C-scorpionate compounds. Tris-2,2,2-(1-pyrazolyl)ethanol, HOCH₂C(pz)₃ (1), one of the most important derivatives of hydrotris(pyrazolyl)methane, was used as a building block for the synthesis of new functionalized C-scorpionates, aiming to expand the scope of this unexplored class of compounds. The first dendritic C-scorpionate was successfully prepared and used in the important industrial catalytic reactions, Sonogashira and Heck C-C cross-couplings.