Development of methods that can convert CO2 to value added chemicals can provide a way to control the excess CO2 in atmosphere which is suspected as a main cause of the global warming. Direct electrochemical CO2 reduction to fuels is one of the promising CO2 utilization technology. In electrochemical system, electrocatalysts are the most important component as they determine the overpotential that is required for reaction to occur and current density of which value reflects how efficiently the reaction occurs. In conventional electrolysis cell, the electrocatalysts deposited over electrodes are submerged in the electrolyte and reaction occurs between catalyst surface and the dissolved substrates. However, for gaseous reagent like in the CO2 reduction reaction, the low solubility of CO2 in the electrolyte can limit the overall efficiency of electrolysis cell. So, to improve CO2 reduction efficiency, both the design of efficient catalysts and the optimization of electrolysis cell are required. In this research, three dimensional porous nickel and nitrogen doped carbon with high surface area was prepared as an efficient CO2 reduction electrocatalyst. And, among the various kinds of electrolysis cell design, membrane electrode assembly (MEA) which has been used in polymer electrolyte membrane fuel cells (PEMFCs) was introduced to facilitate efficient transfer of CO2 to the catalyst surface. Due to the porous structure of catalysts with high surface area and enhanced CO2 transfer by three-phase interface of CO2 (gas), electrolyte (liquid) and catalyst (solid), high current density over 100mA/cm2 with selective CO production of 99 % Faradaic efficiency can be achieved.

Scalable electro-reduction of CO2 to CO with a single atom nickel doped porous carbon electrocatalyst

2019 Spring National Meeting

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