Exploiting renewable energy sources to drive CO₂ reduction electrochemically into value-added products has gained tremendous attention towards reducing the greenhouse effect. Upstream processes for capturing and purifying the CO₂ raise the overall cost of the electrolysis system. Direct reduction of flue gas into value-added C₂₊ products has attained much consideration in recent years. However, the sensitivity of the cathode catalyst performance in the presence of flue gas contaminants, particularly O_2, and strong competition from the hydrogen evolution reaction in aqueous electrolyte are major challenges for such an approach. Herein, the influence of flue gas contaminants on electrochemical reduction of CO₂ in acidic nonaqueous methanol to a methyl formate product has been investigated on a Pb-catalyzed electrode in conjunction with aqueous anolyte for the promotion of a sustainable water oxidation half-reaction. The presence of 4% O₂, 0.05% SO₂, and 0.05% NO is shown to have minimal effect on the total faradaic efficiency of CO₂ reduction products. CO₂ concentration-dependent measurements reveal declining CO₂ reduction faradaic efficiencies corresponding to the decrease in partial pressure, which is attributed to CO₂ mass transfer limitations to the electrode surface. XPS analysis displays the relative stability of the Pb working electrode before and after the electrochemical operation during exposure to flue gas components, which further highlights the promising tolerance of this system for direct flue gas conversion.