Neutron Insights into Sorption Enhanced Methanol Catalysis.

Sorption enhanced methanol production makes use of the equilibrium shift of the hydrogenation reaction towards the desired products. However, the increased complexity of the catalyst system leads to additional reactions and thus side products such as dimethyl ether, and complicates the analysis of the reaction mechanism. On the other hand, the unusually high concentration of intermediates and products in the sorbent facilitates the use of inelastic neutron scattering (INS) spectroscopy.

Hydrogen in methanol catalysts by neutron imaging.

Although of pivotal importance in heterogeneous hydrogenation reactions, the amount of hydrogen on catalysts during reactions is seldom known. We demonstrate the use of neutron imaging to follow and quantify hydrogen containing species in Cu/ZnO catalysts operando during methanol synthesis. The steady-state measurements reveal that the amount of hydrogen containing intermediates is related to the reaction yields of CO and methanol, as expected from simple considerations of the likely reaction mechanism.

Inelastic neutron scattering evidence for anomalous H-H distances in metal hydrides.

Hydrogen-containing materials are of fundamental as well as technological interest. An outstanding question for both is the amount of hydrogen that can be incorporated in such materials, because that determines dramatically their physical properties such as electronic and crystalline structure. The number of hydrogen atoms in a metal is controlled by the interaction of hydrogens with the metal and by the hydrogen-hydrogen interactions.

Hydride Formation Diminishes CO Reduction Rate on Palladium.

The catalytic hydrogenation of CO includes the dissociation of hydrogen and further reaction with CO and intermediates. We investigate how the amount of hydrogen in the bulk of the catalyst affects the hydrogenation reaction taking place at the surface. For this, we developed an experimental setup described herein, based on a magnetic suspension balance and an infrared spectrometer, and measured pressure-composition isotherms of the Pd-H system under conditions relevant for CO reduction.

Rationally Designed Blue Triplet Emitting Gold(III) Complexes Based on a Phenylpyridine-Derived Framework.

A series of blue-emitting phosphorescent mono-cyclometalated Au complexes have been successfully synthesized. Tailoring the substitutions on the phenylpyridine (ppy) ligand scaffold with electron-withdrawing fluorine groups on the phenyl ring to achieve stabilization of the HOMO and an electron-donating dimethylamino group on the pyridine ring to destabilize the LUMO resulted in a large energy gap and bestowed on the gold(III) complexes high-energy emission and high quantum efficiencies. The results of cyclic voltammetry studies suggested a predominantly redox event localized on the cyclometalated ligand.