The electrochemical synthesis of glycerol carbonate from glycerol and potassium carbonate enables utilizing electrical power under mild reaction conditions to upgrade the glycerol waste into valuable glycerol carbonate while consuming carbon dioxide. To further scale up the bench-scale process for industrial application, understanding the reaction mechanism is essential. Conventional electrochemical reaction with carbon dioxide species in acidic and neutral conditions involves carbon dioxide species activation by forcing electron into neutral-charged carbon dioxide species. Under alkaline system of study however, the reductive activation is no longer feasible considering the double negatively-charged carbonate ions impose electrostatic repulsion to electron. The separated cell study reveals that while products formed on both cathode and anode, significantly more product is formed on the anode. This suggests that the glycerol carbonate reaction is oxidative in alkaline system, in contrast to the reductive reaction proposed in acidic and neutral system. This also implies that anodic activation of reactant species is much easier than cathodic activation under alkaline condition, which is reasonable considering both glycerol and carbonate can be easily activated by anodic reaction than cathodic reaction. From the results, the novel alkaline electrochemical production of glycerol carbonate from waste glycerol and carbon dioxide, involves a unique oxidative mechanism different from the conventional acid and neutral system. This confirms the opportunity to bypass the kinetic limit of the conventional system, making the industrial production of glycerol carbonate more economically viable. However, more questions need to be addressed to complete the puzzle of the reaction mechanism, such as the type of intermediate involved and the type of bond broken during reaction.