Electrocatalytic reduction of CO 2 is an effective way to solve environmental issues. In this article, we report an inexpensive, readily available zinc oxide catalyst (TEA-ZnO) functionalized using alkanolamine, which is highly active and selective for the reduction of CO 2 to generate CO at elevated temperatures. Triethanolamine-modified zinc oxide (TEA-ZnO) shows ca. 88.8% CO Faradaic efficiency at −0.84 V vs RHE. The amine groups of triethanolamine could increase the adsorption capacity of CO 2 , expose more CO 2 -specific active sites, and mitigate the high-temperature decrease of CO 2 solubility, which enables TEA-ZnO to maintain high CO 2 selectivity in the temperature range of 0−60 °C.