Electrochemical Reduction of CO2 (ERCO2) on Pb Electrocatalysts using Mn3O4 as Anode

Abstract

The electrochemical reduction of carbon dioxide (ERCO₂) to chemical feedstock and fuels is a promising strategy for reducing excessive carbon dioxide emissions. There are various benefits of converting CO₂ to a single product and Pb is one of the active and efficienct catalyst for reducing CO₂ to HCOOH. The current work used the electro-deposition method to produce manganese oxide (Mn₃O₄) (nano particle flakes) and highly active, low-cost lead (Pb) catalysts with a variety of morphologies (Nano crystal Flakes, Nano wires, and Nano crystal sheets). For the first time, the Mn₃O₄ catalyst was employed as the anode in the water oxidation process to produce protons, and the electrocatalytic effects of Mn₃O₄ and Pb on the ERCO₂ reaction were investigated. The influence of CO₂ reduction on catalyst loading is investigated and the lone product HCOOH is detected on the produced Pb catalysts. Using a systematic electrochemical study, the final product of the ERCO₂ reaction is identified and measured. The maximum Faradaic efficiency was measured on Pb (nano crystal flakes) at −1.003 V, yielding efficiency of 77.32 % (10 min) in 1 mg/cm² catalyst loading and 78.4 % on nano wires (10 min) at −1.003 V in 2 mg/cm² catalyst loading, respectively. More specifically, it is discovered that the reaction selectivity and efficiency of CO₂ electroreduction to HCOOH are highly influenced by the morphology and loading of the catalyst. These results provide an intimate understanding of water oxidation on Mn₃O₄ and CO₂ electroreduction on Pb catalyst.