Study on the catalytic activity of Au-Ti bimetallic nanoparticle on $TiO_2$ support for CO oxidation through DFT method

Abstract

Gold nanoparticles (NP) on $TiO_2$ support have a high catalytic activity in CO oxidation reaction unlike the bulk gold and would be a good candidate to substitute the platinum catalysts in catalytic converter. However, gold NPs have a problem of high cost and deactivation. In this thesis, Au-Ti bimetallic NPs on $TiO_2$ support were studied by means of density function theory (DFT) calculation to solve the problem of Au NP catalysts. For the appropriate result of the $TiO_2$ support, DFT+U method was used in DFT calculation and $U_{eff}$ value for Ti was fitted by the reduction energy of $TiO_2$. On the $TiO_2$ support, Au-Ti bimetallic NPs were more strongly adsorbed than Au monometallic NP. The adsorption energy of $O_2$ was higher on Au-Ti bimetallic NPs than Au monometallic NPs. The energy barrier of CO oxidation reaction was lower in the system of Au-Ti bimetallic NPs. These results suggest that Au-Ti bimetallic NPs have lower deactivation and higher catalytic activity than Au monometallic NPs.