Kim, Juwon Lee, Si Young Kim, Se-Jun Koo, Bonho Chung, Jinkyu Lee, Danwon Choi, Subin Kim, Jimin Seo, Sungjae Nam, Chihyun Gandionco, Karl Adrian Bak, Gwangsu Jo, Sugeun Kim, Namdong Shin, Hyun-Joon Chae, Keun Hwa Won, Da Hye Marcus, Matthew A. Shapiro, David A. Haw, Shu-Chih Alsem, Daan Hein Salmon, Norman J. Min, Byoung Koun Kim, Hyungjun Hwang, Yun Jeong Lim, Jongwoo 2024-11-15T12:00:16Z 2024-11-15T12:00:16Z 2024-11-12 2024-12 2542-4351 https://pubs.kist.re.kr/handle/201004/151068 Revealing and redirecting the dynamic evolution of active species in efficient electrochemical CO2 reduction (ECR) catalysts is challenging. By observing the chemical and morphological evolution in highly efficient ECR catalysts at the nanoscale via operando soft X-ray microscopy, we identified the dynamic transformation of cationic Cu species during operation. The surface Cu2+ phases, observed during a dynamic phase transformation of Cu(OH)2, additionally boost C–C coupling activity beyond the capability of metallic Cu phases. We suggest that copper(II)-carbonate-hydroxide species could dynamically persist under a cathodic environment. By observing the Cu+ phase during the phase transformation and the formation of surface Cu2+ species, we were able to electrochemically redirect low-active catalysts into high-active catalysts for C–C coupling. Density functional theory calculations also support that Cu2+ species could contribute to C–C coupling activity enhancement via ∗CO adsorption energy modulation. English CELL PRESS Spatiotemporal active phase evolution for CO2 electrocatalysis Article 10.1016/j.joule.2024.09.008 1 Joule, v.8, no.12, pp.3373 - 3385 Joule 8 12 3373 3385 N scie scopus 001387211600001 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Chemistry Energy & Fuels Materials Science IN-SITU OXIDATION-STATE REDUCTION COPPER ELECTROREDUCTION CATALYST ORIGIN CU