The electrochemical reduction of CO₂ to useful products has been considered as a promising technology for reducing the greenhouse gas [1]. Among the various products, CO has been targeted in this study since it can be directly used in Fischer-Tropsch process [2]. For CO production, Ag has received the great attention due to its electrocatalytic performance and moderate price compared to other noble metals [3, 4].

To improve the performance of the catalysts, structure engineering to enlarge the surface area have been widely investigated [4, 5]. In particular, fabrication of nano catalysts with large surface area on the carbon paper is required for MEA-type CO₂ electrolyzer for large scale production. For this purpose, electrodeposition is efficient method to fabricate the catalyst on the carbon paper for various gas reduction reactions. In addition, the morphologies and coverage of catalyst layer could be easily controlled using various deposition method such as pulse electrodeposition [6, 7].

In this research, a galvanostatic pulse electrodeposition method was used to fabricate the Ag catalyst on the carbon paper. Increasing the off-time value during the galvanostatic pulse deposition, large surface area was developed. Using the optimized deposition conditions, high current density of CO production was achieved with large surface area of Ag catalysts. The CO production was further enhanced by removal of produced gases bubbles with surfactant.

References

[1] B. Endrődi et al., Progr. Energy Combust. Sci., 62, 133-154 (2017).

[2] Q. Lu et al., Nano Energy, 29, 439-456 (2016).

[3] J. Rosen et al., ACS Catal., 5, 4293-4299 (2015).

[4] Q. Lu et al., Nat. Commun., 5, ncomms4242 (2014).

[5] A. S. Hall et al., J. Am. Chem. Soc., 137, 14834-14837 (2015).

[6] G. Adilbish et al., Int. J. Hydrogen Energy, 42, 1181-1188 (2017).

[7] A. Egetenmeyer et al., Int. J. Hydrogen Energy, 42, 13649-13660 (2017).

*Corresponding author E-mail: jjkimm@snu.ac.kr, Tel: +82-2-880-8863

**Corresponding author E-mail: sookilkim@cau.ac.kr, Tel: +82-2-820-5770