the interaction of the external donor (propyltrimethoxysilane - ptms) with titanium-magnesium catalysts (tmcs) containing dibutylphthalate (dbp) as internal donor, which were prepared in different ways, was studied by chemical analysis and infrared diffuse reflectance spectroscopy (drifts). the chemical composition of the catalysts after their interaction with heptane solutions of ptms, ptms/al...

Experimental studies on the mechanism of copper-catalyzed amination of aryl halides have been undertaken for the coupling of piperidine with iodobenzene using a Cu(I) catalyst and the organic base tetrabutylphosphonium malonate (TBPM). The use of TBPM led to high reactivity and high conversion rates in the coupling reaction, as well as obviating any mass transfer effects. The often commonly emp...

Natural gas may be used instead of hydrogen as fuel for the molten carbonate fuel cell (MCFC) by steam reforming the natural gas inside the MCFC, using a nickel catalyst (internal reforming). The severe conditions inside the MCFC, however, require that the catalyst has a very high stability. In order to find suitable types of nickel catalysts and to obtain more knowledge about the deactivation ...

• Calcium increases Pt-Ge alloy extent by enhancing Ge reducibility. significantly enhances catalyst stability and propylene selectivity. selectively suppresses strong acid sites. Calcium-promoted is less active for coke deactivation, (? d ). Steady state activity increased since Ca decreases ? more than r . The promoting effect of on the catalytic performance Pt 0.5 -Ge 1.5 /Al 2 O 3 during pr...

The stability of a bimetallic Au–Pd/TiO2 catalyst was examined in a packed bed microreactor for the oxidation of cinnamyl alcohol dissolved in toluene. The catalyst was prepared by co-impregnation with a Au–Pd weight ratio of 1 : 19. Experiments were performed at 80–120 °C, oxygen concentration 0–100% and total pressure 4 bara. Principal products observed were cinnamaldehyde, 3-phenyl-1-propano...

● Deactivation of Diesel Catalyst Abstract: The first diesel catalysts, introduced in 1970s for underground mining applications, were simple oxidation catalysts designed for conversion of CO and HC. These catalysts gradually evolved into the modern diesel oxidation catalysts, optimized for PM emission reduction. Future requirements for NOx emission reduction from diesel engines call for new cat...

This paper first describes an empirical model to characterize the deactivation of a catalyst used in the production of a specialty chemical based on actual plant data. This model is then used in a novel multiperiod MINLP optimization formulation that incorporates the empirical model in order to determine the optimal catalyst replacement policy and meet time varying product demand.

A highly active heterogeneous Pd-nanoparticle catalyst for the intramolecular addition of phenols to alkynes was developed and employed in a continuous flow reaction system. Running the reaction in flow mode revealed reaction kinetics, such as the activation energy and catalyst deactivation, and provides many potential practical advantages.

Operando UV/Vis spectroscopy with on-line mass spectrometry was used to study the effect of different types of impurities on the hydrocarbon pool species and the activity of H-SAPO-34 as a methanol-to-olefins (MTO) catalyst. Successive reaction cycles with different purity feedstocks were studied, with an intermittent regeneration step. The combined study of two distinct impurity types (i.e., f...