아래와 같이 초청 세미나를 개최하오니 관심있으신 교수님들의 많은 참여 바랍니다.
■ 제 목 : Electrochemical N2 reduction (NRR) : Aqueous NRR vs. Non-aqueous NRR
■ 연 사 : 최 재 철 / ETRI
■ 일 시 : 2022년 6월 24일(금) 10시 30분
■ Zoom: https://kaist.zoom.us/j/83418316379
■ H o s t : 신병하 교수
■ Abstract :
As an ideal alternative to the Haber-Bosch process, the renewable energy-powered electrochemical N2 reduction to NH3 is a promising approach since the electrochemical reduction can occur under mild conditions; only water and N2 are consumed during overall nitrogen reduction reaction.[1,2] However, the electrochemical reduction of N2 to NH3 (the nitrogen reduction reaction “NRR”) requires the consecutive six-electron/proton transfer reactions to proceed and this leads to the sluggish kinetics, resulting in both low faradaic efficiency (< 10 %) and low yield rates (< 10-10 mole cm-2 s-1) for NH3 synthesis in aqueous electrolytes. Such poor conversion efficiency and yield rates also make it more difficult to confirm the origins of the NH3 production, ie whether it genuinely comes from electrocatalytic NRR, as opposed to some other readily reducible N-containing contaminants (NO, NO2, N2O and doped N atoms in the materials) under reducing potentials. In order to avoid the issues observed in the aqueous NRR and boost up the NRR performance, a Li-mediated approach in non-aqueous electrolytes is recently highlighted due to its fast NH3 production and high faradaic efficiency.
This presentation will conclude with a summary of the critical contaminants leading to false-positive NRR[3-5] and also provide a new approach to enhance the activity of Li-mediated NH3 production using a proton shuttle rather than sacrificial proton source.