Theoretical Study On The Adsorption And Dissociation Of Methanol Over The Heterogeneous Catalyst

As a new-coming build block, methanol plays an important role in chemic industrial process and fuel cell. In view of these exciting challenges it is currently carried out with detailed intensive theoretical and experimental investigations. To achieve its full technological potential, understanding of the reaction mechanism of oxidation, dehydration and dissociation over various metals and catalyst systems is of particular importance. At present, the studies mainly concern the investigation of methanol catalytic reactions on metal (especially, VIII and IB) and oxides, therefore, the theoretical research of the adsorption and dessociation of methanol on solid catalyst maybe in favor of exploiting new catalyst. A detailed discussion of the catalytic reaction of methanol on Cu, Ag, Au and SnO₂ is presented in this paper.First-principles calculations based on density functional theory (DFT), is performed for methanol adsorption and decomposition on several metal and oxides surface. The main contents are organized as the following:(1) Adsorption of methanol on (111) surface of coinage has been investigated by DFT method, at the generalized gradient approximation (GGA) level. The calculations on adsorption energies, structures, mulliken charges, and vibrational frequencies of CH₃OH and CH₃O on clean (111) surface with full-geometry optimization were performed, and the results were agree well with experimental ones. Calculated CH₃OH structure and stretching frequencies and precise determination of adsorption sites can be carried out. Decomposition pathways also have been investigated with transition state search. Methoxyl radical, CH₃O is the decomposition intermediate.(2) DFT based hybrid-method B3LYP has been used to study the interaction of the methanol molecule (CH₃OH) with the Ru(0001) surface (a cluster model, Ru¹⁵).The computed results show that the top site is the favorable adsorption site. The computed geometry for adsorbed CH₃OH agree with the structure proposed from...