Zirconia catalysts doped with Si were prepared by co-precipitation method. The effects of zirconium precursor, precipitant and Si on the selective conversion of ethanol to ethylene over zirconia catalysts were investigated. The addition of Si afforded high surface area and enlarged amount of acidic sites. Higher ethanol conversion and ethylene yield were obtained over SiO2-ZrO2 catalysts. The highest yield of ethylene reached 95.9% over SiO2-ZrO2 synthesized by ZrO(NO3)(2)center dot 2H(2)O and (NH2CH2)(2). [GRAPHICS] .