Periodic density functional and tight-binding quantum chemical molecular dynamics study of catalytic properties on γ-Al2O3 supported Pt catalysts

Growth Pathway of Pt Clusters on α-Al2O3(0001) Surface

“…One of the most important industrial catalysts is alumina-supported platinum, which has been utilized to catalyze a large variety of chemical reactions. − In general, platinum catalysts allow many chemical processes to occur at moderate conditions and alumina possesses superior mechanical and thermal stability. , Recent scanning tunneling microscopy studies by Sartale et al on growth of Pt nanoclusters on the Al 2 O 3 /NiAl(100) substrate revealed that the nanoclusters are mostly randomly distributed on surfaces, with a few exceptions in which some nanoparticles on surfaces are aligned. Theoretically, the catalytic systems are usually represented with a few extremely thin layers, often monolayer, of platinum on the support .…”

“…Theoretically, the catalytic systems are usually represented with a few extremely thin layers, often monolayer, of platinum on the support . Using small Pt clusters on exceedingly small surface unit cells of supports, the interaction between catalysts and support materials was calculated in several theoretical studies. ,, It is expected that chemical reactivity of molecular species on the thin layers of catalytic systems would be considerably different from the ones with higher catalyst loading on the same support due to the support effects. Indeed, theoretical studies showed that in the case of low catalyst loading electron transfer from platinum to the substrate occurs and catalytic activity changes accordingly.…”

Density-Functional Tight-Binding Study of Carbonaceous Species Diffusion on the (100)-γ-Al2O3 Surface

“…The three-way catalyst (TWC) technology is among the innovative catalyst technologies for eliminating the generated hazardous exhaust gases, that is, carbon monoxide (CO), nitrogen oxides (NO x ), and unburnt hydrocarbons (C x H y ) from vehicles. − The catalysts are composed of, and not limited to, noble metals (Pt, Pd, or Rh) and metal oxides. The commonly used metal oxides that support TWC are alumina (Al 2 O 3 ), − zirconia (ZrO 2 ), − and ceria (CeO 2 ). − Experimental − and theoretical − studies were performed extensively for exploring the catalytic activity and elucidating the reaction mechanism. , During the removal process, CO and C x H y are oxidized into CO 2 , whereas NO x is reduced to N 2 . In such reactions, the C x H y oxidation leads to the formation of intermediates reported in ref , namely, oxygenated carbonaceous (oxy-carbon) species.…”

Electronic structure and electrical conductivity of MgO protecting layer in plasma‐display panels: A tight‐binding quantum chemical study

“…From an engineering point of view, it is indispensable to develop a more effective method which will enable the use of a large-scale model. In this regard, we have developed an original tight-binding quantum chemical molecular dynamics program, Colors, [7][8][9][10][11] which is over 5000 times faster than the conventional first-principles quantum chemical molecular dynamics simulator. This code enables us to realize large-scale calculations for elucidating the chemical-reaction dynamics in more-complicated systems.…”