Ethanol Electro‐oxidation in Aqueous and Poly(acrylic acid)‐Based Gel Alkaline Electrolytes, Varying the Pd x Ag y Composition by using Differential Pulse Amperometry

In this work, we prepared a polymer gel based on poly (acrylic acid) partial potassium salt (PAA‐K) for its use as an electrolyte in the ethanol electro‐oxidation. In addition, we synthesized Pd x Ag y materials by varying the metallic ratio through differential pulse amperometry (DPA). These materials showed particle sizes ranging from 40 to 60 nm, and their compositions were Pd 75 Ag 25 , Pd 60 Ag 40 , and Pd 50 Ag 50 , as determined by X‐ray fluorescence. Electrocatalytic evaluation of ethanol oxidation in aqueous electrolyte at 1.0 M ethanol resulted in the following activity trend: Pd 60 Ag 40 >Pd 50 Ag 50 >Pd 75 Ag 25 ≥Pd, where Pd 60 Ag 40 showed the highest current density with 102.6 mA mg −1 Pd. In the PAA‐K gel electrolyte, Pd 60 Ag 40 also achieved the highest peak current density (7.5 mA mg −1  Pd). Additionally, Pd 60 Ag 40 maintained almost the same oxidation potential (−0.41 V vs . NHE) in aqueous and gel electrolytes, but the current density decreased 13.7‐fold owing to the high viscosity of PAA‐K electrolyte (∼400 cP).