In situ Raman spectroscopy is rapidly becoming a very popular catalyst characterization method because Raman cells are being designed that can combine in situ molecular characterization studies with simultaneous fundamental quantitative kinetic studies. The dynamic nature of catalyst surfaces requires that both sets of information be obtained for a complete fundamental understanding of catalyti...

The bifunctional nature of Cu-ALOx-on-carbon catalysts, used in the direct catalytic conversion of ethanol to ethyl acetate, prompted an examination of the dispersion of Cu on the composite catalyst. For this, the NzO-method of Osinga et al. for estimation of bare metallic copper surface on composite copper catalysts has been adapted for use on a gravimetric adsorption unit and Ohen applied to ...

Steady-state isotopic-transient kinetic analysis (SSITKA) is a very useful technique for the kinetic study of heterogeneous catalytic reactions. Initially developed by Happe1,l Bennett,2 and Biloen? SSITKA has been used in a number of studies to determine in situ kinetic information about the reaction mechanism and the catalyst-surface reaction intermediates. The technique is based upon the det...

The beautiful target and spiral patterns exhibited by the Belousov-Zhabotinsky (BZ) reaction in thin films of solution are representative of spatiotemporal behavior in a two-dimensional, planar excitable medium. 14 We report here BZ chemical waves propagating on the two-dimensional surface of a sphere. Singleand double-rotor spiral waves develop on the surface of a single cation exchange bead, ...

The surface and near-surface region of an active catalyst and the adjacent gas-phase reactants were investigated simultaneously under reaction conditions using in situ X-ray photoelectron spectroscopy (XPS). This investigation of methanol oxidation on a copper catalyst showed that there was a linear correlation between the catalytic activity of the sample and the presence of a sub-surface oxyge...

Active sites are created on the surface of a Li/MgO catalyst used for the selective oxidation of methane by the gradual loss of carbondioxide from surface carbonate species in the presence of oxygen. Decomposition of the carbonat~ species in the absence of oxygen is detrimental to the activity of the cataIy~t. The active sites'created are not stable but disappear either as a result of reaction ...

A supported trimetallic nano catalyst and a fixed bed catalytic process have been developed for the conversion of CO2 + H2O (in the form of steam) + 1% H2 to alcohol and propyne The mixture of CO2 +H2O and H2 is passed over Ru:Mn:Ni nano catalyst dispersed on a high surface area antase titanium dioxide catalyst support at 773 K and at atmospheric pressure with the gas space velocity of 6000-700...

Well-defined model catalyst samples, prepared under ultra-high-vacuum (UHV) conditions, hold the potential of bridging the gap between traditional surface science and technical catalysis studies. However, work remains to understand and characterize reaction kinetics of such samples under more realistic pressure conditions, specifically, how reaction kinetics of a well-studied reaction (such as ...

In our former work [Catal. Today 174 (2011) 127], 12 heterogeneous catalysts were screened for CO oxidation, and Au-ZnO/Al2O3 was chosen and optimized in terms of weight loading of Au and ZnO. The present study follows on to consider the impact of process parameters (catalyst preparation and reaction conditions), in conjunction with catalyst composition (weight loading of Au and ZnO, and total ...

We demonstrate selective functionalization of independently addressed microelectrodes by electrochemical activation and deactivation of a coupling catalyst. 1,2,3-Triazole formation between terminal acetylenes and organic azides is efficiently catalyzed by copper(I) complexes (a Sharpless "click" reaction), while the oxidized copper(II) complexes are inactive. By electrochemically activating or...