Abstract: Al₂O₃ supported Pt and Pd nanoparticle catalysts were prepared by impregnation-reduction method, and employed in the photocatalytic aqueous-phase reforming of ethylene glycol. Light illumination can decrease the reaction activation energy remarkably. Pt/Al₂O₃ exhibits much higher H₂ turnover frequency (TOF) and lower CO selectivity than Pd/Al₂O₃ catalyst. Their morphology and structure were characterized by XRD, TEM, UV-vis techniques. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) indicates light can promote the cleavage of O-H bonds of ethylene glycol molecule. DFT calculation suggests the lower CO selectivity over Pt/Al₂O₃ catalyst can be attributed to the low energy barriers of reaction in the step of CO+O→CO₂.