Taguchi method of experimental design was used to optimize the catalyst preparation conditions of the sol-gel method to design a Pt-SnO2/AlO3 catalyst for the low temperature oxidation of carbon monoxide in hydrogen rich stream. HNO3, H2O, aluminum nitrate concentrations and the stirring rate in sol-gel process were optimized to obtain the maximum CO conversion using Taguchi method. It was found and experimentally verified that lower levels of HNO3 and H2O concentrations and higher levels of aluminum nitrate concentration and stirring rate maximized CO conversion without inversely affecting selectivity. The effects of reaction conditions such as temperature, time-on-stream, O-2 concentration. CO concentration and space velocity on CO conversion and selectivity were also investigated in a microreactor flow system using the optimum catalyst obtained. A 100% CO conversion was obtained with reasonable selectivity at a temperature of 100degreesC, CO concentration of 0.5-1.1 %, O-2/CO ratio of about 2 and space velocity of 24,000 cm(3)/(g h). 0 2003 Elsevier B.V. All rights reserved.