In this study, we investigate the adsorption properties of Pt-doped and-substituted silicene by means of first-principles computations. The Pt adsorption and substitution on silicene are able to change the electronic structure remarkably. We find that Pt atom prefers to bind silicene on hollow site with high adsorption energy -5.815 eV. For the substitution of single Pt atom in silicene lattice, 4.401 eV energy is required. Both of the systems have good catalytic properties and have a potential for sensor technology. Especially, catalytic oxidation of CO on Pt-embedded silicene is investigated and it is found that Eley-Rideal (ER) mechanism with a two step route is a suitable way to produce CO2 from CO and activated O-2. (C) 2016 Elsevier B.V. All rights reserved.