Heterogeneous Catalysis and Solid Catalysts

Dehydration of 2‐Octanol over Ca‐doped CeO2 Catalysts

“…Dehydration of alcohols to olefins or ethers is known to be catalyzed by metal oxides . Alumina has been extensively studied for this reaction . Other oxides such as ZrO 2 and rare earth oxides have been examined as well.…”

“…Although the mechanism of catalytic dehydration has been studied for many years, it is not yet fully understood . Some have agreed that dehydration proceeds through an E2‐like reaction intermediate, which exhibits a certain degree of ionic character; with increasing reaction temperature, the structure of the transition state changes from E2‐like to E1‐like .…”

NOx reduction on a transition metal-free γ-Al2O3 catalyst using dimethylether (DME)

“…Although it is difficult to obtain quantitative information regarding the relative abundances of these transformed hydroxyl species, our results are consistent with former studies where similar negative features were commonly observed during the adsorption of various probe molecules on alumina. It was reported that the vibrational frequencies of these features are virtually invariant for different probe molecules [12,[14][15][16][17][22][23][24]37,[42][43][44]. In these extensive former reports, the formation of these negative IR bands were attributed to the interaction of isolated hydroxyl groups on the alumina surface with the probe molecule, which resulted in the disappearance of the isolated -OH groups and the appearance of a broad IR band within 3400-3600 cm…”

“…These former studies [12,[14][15][16][17][22][23][24]37,[42][43][44] can guide us to assign the types of isolated surface hydroxyl groups which are interacting with the surface NO x species that are formed upon NO 2 adsorption. Considering the frequency values of these negative features, it can be argued that NO x species interact with the different types of OH groups (I a , II a , and III) discussed in detail by Knozinger and Ratnasamy [43].…”

Aktivált ketonok cinkona alkaloidokkal módosított heterogén katalitikus enantioszelektív hidrogénezése, folyamatos áramú rendszerben

“…Ez egy olyan reakció séma, amely képes feltérképezni a lehetséges molekuláris viszonyokat, melyet közvetlen megfigyelések vagy közvetett kísérleti bizonyítékok alapján feltételezhetünk [83]. A mechanisztikus modellek alapját a katalízis kísérleti eredményei, a molekuláris modellezés és a fizikaikémiai mérımódszerek által meghatározott katalizátor-módosító-szubsztrát rendszer kölcsönhatásai képezik.…”