Electrochemical Methane Activation and Conversion Using Fe, Co, Cu Oxides/ZrO2 Nanocomposites

Abstract

Methane has been widely employed as a feedstock for numerous chemical and electrochemical processes. However, methane activation poses a challenge due to the molecule’s relative inertness, lack of significant polarity and because its bond energy is the highest among all hydrocarbons. Consequently, the ability to activate methane (CH4), or access the C atom to form new bonds is a difficult endeavor [1]. Furthermore, CH4 gas emission has long been ignored and regarded as a trivial matter [2], even though its effect as a greenhouse gas is over 30 times more potent than that of CO2 [3]. In this regard, the oxidation and conversion of CH4 to liquid alcohols is an economical and energy efficient alternative with academic and industry interest. The present study shows the synthesis and characterization of Fe, Co, Cu oxides/ZrO2 nanocomposites used as bifunctional electrocatalyst for the electrochemical activation of methane, which in conventional alkaline electrochemical systems is always performed at room temperature. Fe, Co, Cu oxides/ZrO2 nanocomposites were synthesized using an aqueous-phase precipitation technique and their structural, spectroscopic, magnetic and electrochemical characteristics were evaluated. Methane was electrochemically activated over the three functional electrocatalysts here synthesized. Carbonate anions were used as an oxygen donator to facilitate methane activation while ZrO2 adsorbed and donated carbonate anions to active sites on Fe, Co and Cu oxides where methane was adsorbed and activated. Products formed were studied by gas chromatography.