The　adsorption/desorption　of　the　key　intermediate　at　the　molecular　level　in　CO2　hydrogenation　deserves　significant　attention　since　the　intermediate　stability　can　greatly　affect　the　products　selectivity.　In　this　paper,　the　Pt/Cd-TiO2　catalysts　were　synthetized　by　impregnation　method.　The　Pt/Cd-TiO2　catalyst　is　characterized　through　X-Ray　diffraction(XRD),　H2-temperature　programmed　reduction(H2-TPR),　Raman　spectra,　electron　spin　resonance　(ESR),　transmission　electron　microscope(TEM),　X-ray　photoelectron　spectroscopy(XPS),　CO2　temperature　programmed　desorption(CO2-TPD),　and　N2　sorption　experiments.　With　the　introduction　of　Cd2+,　CO　selectivity　increases　to　98.1%　and　CH4　selectivity　decreases　to　1.9%　over　Pt/Cd-TiO2　compared　to　Pt/TiO2(87.5%　for　CO　and　12.5%　for　CH4)　during　CO2　hydrogenation.　Additionally,　CO　was　produced　at　225　degrees　C　over　Pt/Cd-TiO2,　which　is　25　degrees　C　lower　than　Pt/TiO2　catalyst(250　degrees　C).　In　situ　FTIR　and　XPS　measurements　reveal　that　the　Cd2+　could　reduce　the　electron　density　of　Pt　nanoparticles(Pt　NPs),　and　the　reduced　electron　density　of　Pt　NPs　will　contribute　to　the　desorption　of　adsorbed　COads　into　CO　in　the　gas　phase　and　inhibit　the　hydrogenation　of　COads　to　produce　CH4.　During　CO　methanation　contrast　experiments,　CH4　evolution　decreases　by　approximately　6.6　times　with　the　introduction　of　Cd2+,　indicating　that　Cd2+　hinders　the　reaction　of　CO　with　H　to　produce　CH4,　in　accordance　with　the　increased　CO　selectivity　in　CO2　hydrogenation　over　Pt/Cd-TiO2.　The　CO　selectivity　was　all　improved　over　Pt/TiO2　promoted　with　several　cations(Cd2+,　Mn2+,　Ba2+,　K+　and　Na+),　and　Pt/Cd-TiO2　exhibits　the　highest　CO　selectivity.　This　study　sheds　light　on　the　enhanced　CO　evolution　over　Pt/Cd-TiO2　in　CO2　hydrogenation　and　provides　guidance　for　catalyst　design.