α-d-Glucopyranose Adsorption on a Pd30 Cluster Supported on Boron Nitride Nanotube

Abstract

Boron nitride nanotube (BNNT) as an innovative support for carbohydrate transformation processes was evaluated, using density functional theory. The a-D-glucopyranose adsorption on a Pd 30 cluster, supported on BNNT, was used to check both the local activity of topologically different metallic sites and the effects of the proximity of the BNNT surface to the same metallic sites. Detailed geometrical and electronic analyses performed on Pd 30 /BNNT and a-D-glucopyranose/Pd 30 /BNNT systems were discussed. It was observed that the deposition of the Pd 30 cluster onto the BNNT support gives rise to an electronic rearrangement, determining a charge transfer from the support to the adsorbed metal cluster. The charge transfer, as shown by the analysis of molecular electrostatic potential, seems to generate electron-rich and electron-poor zones in the Pd 30 cluster. The a-D-glucopyranose species, regardless the interaction geometry experienced, acts as an electron donor and preferentially adsorbs close to the electron-poor metal/support interface.

Boron Nitride‐supported Sub‐nanometer Pd6 Clusters for Formic Acid Decomposition: A DFT Study

“…Bader charge analysis indicates negligible charge transfer between the cluster and the support. It is interesting to compare this latter result with that of Prestianni et al . regarding the interaction of a Pd 30 cluster on a BNNT surface.…”

On the Acid Sites of Phosphorous Modified Zeosils

“…Alcohol dehydration has been extensively used as a probe reaction to characterize acidity in zeotype materials, 6,[35][36][37][38] and recent computational as well as experimental studies have led to detailed understanding of underlying reaction mechanisms and pathways of light (C1-C4) alcohol dehydration on solid acid catalysts. 37,[39][40][41][42][43][44][45][46][47] The ubiquitous themes tying these studies together are: (i) the evidence for the coupling of unimolecular and bimolecular dehydration pathways, where adsorbed dimers that produce di-alkyl ethers (bimolecular dehydration product) can also contribute to olefin formation (unimolecular dehydration product), 43,44 (ii) inhibition of olefin formation rates at high alcohol partial pressures (> 50 torr) due to the higher stability of adsorbed alcohol dimers relative to monomers, 37,39 and (iii) an increased preference to unimolecular dehydration with increasing temperatures. 37,39,43,44 The favorability of E1/E2 elimination pathways during alcohol dehydration on zeolites depends on the stability of carbenium formed during the prominence of E2 type pathways as the RDS for isopropanol (a secondary alcohol) dehydration in aluminosilicates MFI, 41,48 and FAU, 41 primary alcohol dehydration primarily occurs through E1-type elimination pathways.…”

“…37,[39][40][41][42][43][44][45][46][47] The ubiquitous themes tying these studies together are: (i) the evidence for the coupling of unimolecular and bimolecular dehydration pathways, where adsorbed dimers that produce di-alkyl ethers (bimolecular dehydration product) can also contribute to olefin formation (unimolecular dehydration product), 43,44 (ii) inhibition of olefin formation rates at high alcohol partial pressures (> 50 torr) due to the higher stability of adsorbed alcohol dimers relative to monomers, 37,39 and (iii) an increased preference to unimolecular dehydration with increasing temperatures. 37,39,43,44 The favorability of E1/E2 elimination pathways during alcohol dehydration on zeolites depends on the stability of carbenium formed during the prominence of E2 type pathways as the RDS for isopropanol (a secondary alcohol) dehydration in aluminosilicates MFI, 41,48 and FAU, 41 primary alcohol dehydration primarily occurs through E1-type elimination pathways. 37,39,40,[43][44][45][46][47] To better understand the active centers of P-zeosils, we sought to compare the kinetics of isopropanol (IPA) dehydration over the two families of catalysts (aluminosilicates and P-zeosils).…”

A Combined Theoretical and Experimental Approach for Platinum Catalyzed 1,2-Propanediol Aqueous Phase Reforming

“…In recent investigations, we demonstrated the possibility to use purposely shaped clusters for determining reaction mechanisms in the case of dehydrogenation of lignan-derivitives on gold , and of 2-methyl-3-butyn-2-ol hydrogenation on palladium . The same approach was established to be valid also in the analysis of catalyst modification and structure–activity relationships .…”