A new series of electrocatalysts consisting of Ag nanoparticles supported on graphitic carbon nitride (g-C3N4) are presented. The combination of nanostructured silver and a carbon nitride support results in the direct generation of synthesis gas (CO+H2) during the electrocatalytic reduction of CO2 in water. By using a state-of-the-art electrocatalytic setup, the influence of different operation parameters over the final product composition is shown. The H2/CO product ratio can easily be tuned from 100:1 to 2:1 with high reproducibility by controlling the applied potential and the Ag loading. More importantly, long-term and catalyst reuse experiments demonstrate the robustness of these electrodes, which could be operated for over 20 h time on stream and reused several times without any evident loss of activity or selectivity. Our results highlight the potential of nanostructuring Ag-based catalysts and the relevance of the selected support for the green valorization of CO2.