Cu is unique in its ability to produce gas-phase nitric oxide in acidic electrolyte, a critical intermediate for the formation of benign dinitrogen. If nitric oxide binds strongly to the surface it instead dissociates, leading to hydrogenated products such as hydroxylamine or ammonium. In alkaline electrolyte nitrite desorbs from Cu as the primary product, with ammonium and hydroxylamine forming as secondary products. The NO3RR is therefore of interest as a green alternative to the carbon dioxide-intensive thermal Haber-Bosch process, producing ammonium via treatment of waste streams with renewable electricity. While studies in acidic and alkaline electrolytes have progressed mechanistic understanding of the role of pH on NO3RR selectivity, sources of aqueous nitrate (e.g. groundwater, wastewater, nuclear wastewater) are typically circumneutral. Several studies have investigated Cu in neutral electrolytes, though are typically performed in unbuffered electrolytes (e.g. sodium sulfate, sodium perchlorate, or sodium carbonate) where proton-concentration gradients at the electrode surface impact the electrochemical driving force. Furthermore, missing are studies investigating the role of phosphate ions-on NO3RR as a buffering agent, specifically-adsorbing anion, and Faradaic competitor in side reactants.