Effect of Ionomer Content and Ag/C Catalyst Surface Area on the Performance of CO<sub>2</sub> Electrolysis to CO
Khaled Seteiz, Josephine N. Häberlein, Philipp A. Heizmann, Luca Bohn, Severin Vierrath, Joey Disch
Abstract
High Resolution Image Download MS PowerPoint Slide Carbon-supported silver catalysts have proven high activity and durability in the electrochemical reduction of CO 2 to CO. This work investigates the impact of cathode catalyst layer composition on performance by varying the ionomer content and Ag/C catalysts with differing BET surface areas (33–455 m 2 g –1 ). For optimal performance, there is a positive correlation between optimal ionomer binder content and catalyst surface area: 5 wt % PiperION for Ag/C Super P, 15 wt % PiperION for Ag/C Vulcan, and 25 wt % PiperION for Ag/C Ketjen . The top-performing cells exhibited remarkably high CO faradaic efficiencies of 93% for 15 wt % Ag/C Vulcan, 91% for 5 wt % Piperion Ag/C Super P, and 90% for 25 wt % Piperion Ag/C Ketjen (all at 400 mA cm –2 with 0.01 M CsOH as anolyte). Long-term measurements at 300 mA cm –2 over 100 h revealed the lowest FE CO loss for Ag/C Vulcan, decreasing from 93 to 87%, followed by Ag/C Super P (91–79%) and Ag/C Ketjen (90–63%).