Achieving Selective and Efficient Electrocatalytic Activity for CO2 Reduction Using Immobilized Silver Nanoparticles

Cheonghee Kim; Hyo Sang Jeon; Taedaehyeong Eom; Michael Shincheon Jee; Hyungjun Kim; Cynthia M Friend; Byoung Koun Min; Yun Jeong Hwang

doi:10.1021/jacs.5b06568

Achieving Selective and Efficient Electrocatalytic Activity for CO2 Reduction Using Immobilized Silver Nanoparticles

J Am Chem Soc. 2015 Nov 4;137(43):13844-50. doi: 10.1021/jacs.5b06568. Epub 2015 Oct 20.

Authors

Cheonghee Kim¹, Hyo Sang Jeon^{1

2}, Taedaehyeong Eom³, Michael Shincheon Jee^{1

4}, Hyungjun Kim³, Cynthia M Friend⁵, Byoung Koun Min^{1

2

6}, Yun Jeong Hwang^{1

2}

Affiliations

¹ Clean Energy Research Center, Korea Institute of Science and Technology , Seoul 02792, Republic of Korea.
² Korea University of Science and Technology , Daejeon 34113, Republic of Korea.
³ Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST) , Daejeon, 34141, Republic of Korea.
⁴ Department of Chemical and Biological Engineering, Korea University , Seoul 02841, Republic of Korea.
⁵ Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States.
⁶ Green School, Korea University , Seoul 02841, Republic of Korea.

PMID: 26447349
DOI: 10.1021/jacs.5b06568

Abstract

Selective electrochemical reduction of CO2 is one of the most sought-after processes because of the potential to convert a harmful greenhouse gas to a useful chemical. We have discovered that immobilized Ag nanoparticles supported on carbon exhibit enhanced Faradaic efficiency and a lower overpotential for selective reduction of CO2 to CO. These electrocatalysts were synthesized directly on the carbon support by a facile one-pot method using a cysteamine anchoring agent resulting in controlled monodispersed particle sizes. These synthesized Ag/C electrodes showed improved activities, specifically decrease of the overpotential by 300 mV at 1 mA/cm(2), and 4-fold enhanced CO Faradaic efficiency at -0.75 V vs RHE with the optimal particle size of 5 nm compared to polycrystalline Ag foil. DFT calculations enlightened that the specific interaction between Ag nanoparticle and the anchoring agents modified the catalyst surface to have a selectively higher affinity to the intermediate COOH over CO, which effectively lowers the overpotential.