Formate Fuel Production From the Electroreduction of CO2 on Nanostructured SnOx Coated on Gas Diffusion Electrode

Abstract

Due to the extensive use of non-renewable fossil fuels, the crisis in energy is growing, and the gas CO2, which is a product of the burning of hydrocarbons, is contributing to global warming and to acidification of the oceans. Therefore, the issue about carbon dioxide (CO2) capure, sorage and utilization has inspired intensive interests. [2,3] In the various methods of CO2 utilization and recycling, electrochemical reduction of CO2 to transform to useful chemicals or fuels is a potentially efficient way. However, in the procesure of CO2 electroreduction, there is a challenge of the slow kinetic of CO2 electroreduction. [4,5] Overcoming the problems of CO2 reduction under mild conditions would enable solve the energy crisis and the global warming. In the past few decades, researchers found that many metal oxide nanopowders could be the perfect catalysts in the CO2 electroreduction for their controllable various morphologies.[1] In this work, we report the synthesis of SnOx nanocatalysts loaded on the multi-walled carbon nanotubes (MWCNTs), which electrochemical catalyzed CO2 to formate, HCOOH, on the room-temperature with an electrochemical cell having a catalytic SnOx cathode. We controlled different special morphologies by one-step hydrothermal method from SnCl2 precursors. The highest faradaic and energy efficiencies of 65% and 28% were obtained at −1.40 V vs. SCE with particles that were obtained by KOH reduction from a SnCl2 precursor and showed excellent stability in prolonged electrolysis.