Density Functional Theory study of ethanol and formic acid adsorption on CaO(001)

ALFREDO JUAN; VALERIA ORAZI; PABLO BECHTHOLD; ESTELA GONZÁLEZ; JORGE MARCHETTI; PAULA JASEN

Conferencia; 5th International Conference on Applied Surface Science; 2022

Ethanol and formic acid adsorption on CaO (0 0 1) surface at lowcoverage is studied using Density Functional Theory (DFT) calculations with vander Waals corrections. We investigated the CaO surface in its rock saltstructure. The more favorable sites for C2H5OH adsorption are on one (or two)Ca cations bonding the O atom from ethanol. H form (OH group) bond to surfaceoxygens with an adsorption energy of -1.12 (-1.14) eV. The distance of ethanolto surface is in the range of 2.3 - 2.5 Å . The molecule presents a strongelongation of the adsorbed O-H group being 53% (51%) larger that its moleculardistance. Bond order analysis shows that distances and BO are similar for Ca-Omolecule and Ca-O surface. A charge transfer occurs from O atom of the 2ndlayer to Ca ions at 1st layer and the molecular O atom gain some charge, whileH loses charge towards surface oxygen and from this to the rest of the surface.In the case of H-COOH we found two possible adsorption sites with -2.38 and-2.07 eV, again the O-H bond is elongated with respect to the molecular states.DOS and bonding analysis are performed in both cases.@font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:roman;mso-font-pitch:variable;mso-font-signature:-536870145 1107305727 0 0 415 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:swiss;mso-font-pitch:variable;mso-font-signature:-536859905 -1073732485 9 0 511 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin-top:0cm;margin-right:0cm;margin-bottom:10.0pt;margin-left:0cm;line-height:115%;mso-pagination:widow-orphan;font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-ansi-language:ES-AR;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:11.0pt;mso-ansi-font-size:11.0pt;mso-bidi-font-size:11.0pt;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}.MsoPapDefault{mso-style-type:export-only;margin-bottom:8.0pt;line-height:107%;}div.WordSection1{page:WordSection1;}