Selective synthesis of isobutene from syngas is a promising route, but still in a great challenge, to realize the isobutene production from non-petroleum carbon resources. In this work, aiming at realizing more efficient isobutene synthesis from syngas, a series of ZrO2-based catalysts with varied amount of Zn dopant as promoter, were prepared and studied. The catalytic performance of pure ZrO2 and new ZnxZryOz catalysts with Zn/Zr of different molar ratio was evaluated, and the Zn1Zr300Oz catalyst exhibited promoted isobutene selectivity, better than other catalysts. In order to disclose the promotional role of Zn dopant to the enhanced catalyst performance, XRD, TEM, NH3/CO2-TPD and in-situ FTIR techniques were employed. The characterization results revealed that trace amount of Zn dopant could affect the acidic-basic properties and the adsorbed species of the ZnxZryOz catalysts. The CO2-TPD analysis proved that the incorporation of Zn could clearly enhance the surface basicity of ZnxZryOz catalysts. The in-situ FTIR analysis uncovered that the peak intensity of formate and carbonate species on the surface of ZnxZryOz catalysts was different. The optimal Zn1Zr300Oz catalyst displayed more moderate basic sites and less strong acidic sites. It also exhibited the strongest intensity of formate species and the weakest intensity of carbonate species. These specific features of Zn1Zr300Oz catalyst should be beneficial to the synthesis of isobutene from syngas.