5-hydroxymethyl furfural (HMF) electrochemical conversion is a promising method for producing polymer and fuel precursors such as 2,5- Bis(hydroxymethyl)furan (BHMF), and 5,5-bis(hydroxymethyl)hydrofuroin (BHH) [1]. Research on this topic has mainly focused on electrode material selection and synthesis [2], whereas our focus has been on electrode-electrolyte interface modification. Thus, we developed a method to study electrochemical reduction of HMF on silver and glassy carbon [3] using different Alkyl Ammonium Bromide Salts (single and double charged) as an electrode-electrolyte interface modifier. Modifiers not only affect the side hydrogen evolution reaction but also accessibility to reduction centers and selectivity towards target products. In the presence of a variety of reagents, electrochemical real-time mass spectrometry (EC-RTMS) [4] was used to analyze the relative product distributions impacted by the potential of both electrode materials. More quantitative results were obtained from performing steady-state potentiostatic electrolysis of HMF in a flow reactor coupled with a gas chromatograph (GC) and high-performance liquid chromatography (HPLC) to support the results from EC-RTMS. Our research illustrates the impact of different AAB salts on the product distribution in the reduction pathway of HMF towards value added products.