Ce0.88Si0.1Pt0.02O2-δ and Ce0.88Al0.1Pt0.02O2-δ catalysts were synthesized by using a low-temperature sonochemical method and characterized by using XRD, TEM, XPS, FTIR, and BET surface analyzer. The catalytic activities of these compounds were investigated for the water-gas shift reaction in the temperature range of 140-440°C. The substitution of Si in Ce0.98Pt0.02O2-δ increased the releasing capacity of lattice oxygen, whereas the substitution of Al decreased the reducibility of Ce0.98Pt0.02O2-δ, as evidenced by hydrogen temperature-programmed reduction studies. However, both the catalysts showed a considerable improvement in terms of activity and stability compared to Ce0.98Pt0.02O2-δ. The combined activity measurement and characterization results suggest that the increase in the oxygen vacancy, which acts as a dissociation center for water, is the primary reason for the improvement in the activity of modified Ce0.98Pt0.02O2-δ. Both the catalysts are 100% selective toward H2 production, and approximately 99% conversion of CO to CO2 was observed at 260 and 270°C for Ce0.88Si0.1Pt0.02O2-δ and Ce0.88Al0.1Pt0.02O2-δ, respectively. These catalysts do not deactivate during the daily startup/shutdown operations and are sustainable even after prolonged reaction. Notably, these catalysts do not require any pretreatment or activation during startup/shutdown operations. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.