The hydrogenation of carbon monoxide and carbon dioxide on various steel catalysts was studied in the temperature range of 800" to 1,300'F. and at pressures from 5 to 30 atm. The feed gases (3.75 to 20 SCFH) were passed over a catalyst bed of 1/8-h. steel balls supported in a brass-lined reactor 0.81 in. in d i m . The percentage of carbon oxides in the feed was 30% in the runs using a Hz-COZ f...

Reaction mechanisms for the catalytic hydrogenation of CO2 by faujasite-supported Ir4 clusters were studied by periodic DFT calculations. The reaction can proceed through two alternative paths. The thermodynamically favoured path results in the reduction of CO2 to CO, whereas the other, kinetically preferred channel involves CO2 hydrogenation to formic acid under water-free conditions. Both pat...

The combination of the readily available chiral bisphosphine ligand Difluorphos with [Ir(COD)Cl](2) in THF resulted in a highly efficient catalyst system for asymmetric hydrogenation of quinolines at quite low catalyst loadings (0.05-0.002 mol%), affording the corresponding products with high enantioselectivities (up to 96%), excellent catalytic activities (TOF up to 3510 h(-1)) and productivit...

A new approach to optically active N-methylamino acids is presented, relying on stereoselective reduction of N-methylisoxazolinium salts with a dioxyethyl side-chain. The diastereoselectivity of the reduction step is studied systematically, in comparison with that of respective isoxazolines. A two-step transformation of isoxazolinium salts – with NaBH3(OAc) and subsequent catalytic hydrogenatio...

Heterogeneous catalysis is commonly governed by surface active sites. Yet, areas just below the surface can also influence catalytic activity, for instance, when fragmentation products of catalytic feeds penetrate into catalysts. In particular, H absorbed below the surface is required for certain hydrogenation reactions on metals. Herein, we show that a sufficient concentration of subsurface hy...

Few methods permit the hydrogenation of alkenes to a thermodynamically favored configuration when steric effects dictate the alternative trajectory of hydrogen delivery. Dissolving metal reduction achieves this control, but with extremely low functional group tolerance. Here we demonstrate a catalytic hydrogenation of alkenes that affords the thermodynamic alkane products with remarkably broad ...

Organometallic catalysis most often proceeds through a catalytic cycle that involves the coordination of the substrate, either by ligand substitution or by oxidative addition, transformation of the coordinated substrate, and liberation of the product, either by decoordination or by reductive elimination.[1] Classical examples that have been studied in great detail are the hydrogenation of olefi...

The adsorption and kinetics of conversion of cis-2-butene with deuterium on model supported Pd catalyst (Pd/Fe3O4/Pt(111)) were characterized by reflection-absorption infrared spectroscopy (RAIRS), temperatureprogrammed desorption (TPD), and isothermal molecular beam (MB) experiments. It was found that selectivity toward cis-trans isomerization and hydrogenation depends critically on the nature...