Titanium dioxide with CoB amorphous alloys nanoparticles deposited on the surface is known to exhibit higher catalytic activity than the CoB amorphous.A study of the structure of such system is necessary to understand this effect.A quantum chemical study of Co2B2 on the TiO2(110) surface was studied using periodic slab model within the framework of density functional theory(DFT).The results of geometry optimization indicated that the most stable model of adsorption was Co2B2 cluster adsorbed on the hollow site of TiO2 .The adsorption energy calculated for Co2B2 on the hollow site was 439.3 kJ/mol.The adsorption of CO and O2 was further studied and the results indicated that CO and O2 are preferred to adsorb on the Co2 site.Co-adsorption of CO and O2 shows that Co2B2 /TiO2 is a good catalyst for the oxidation of CO to carbon dioxide in the presence of oxygen.