NSRRC Activity Report 2023

Chemical Science 027 T he escalating concentration of atmospheric CO 2 has led to severe global warming and climate change. The electrochemical CO 2 reduction reaction (CO 2 RR) is regarded as a promising avenue for both alleviating CO 2 levels while concurrently yielding valuable products such as ethylene and ethanol. The utilization of a flow cell is pivotal for establishing an industrially viable CO 2 RR process, substantially amplifying catalytic performance, especially in terms of catalytic current density, with enhancements ranging from ten to a hundredfold. This highlights the distinctive catalytic environment and behavior characteristics of a flow cell. To unveil the authentic properties of a catalyst within a flow cell, Sung-Fu Hung (National Yang Ming Chiao Tung University) and his team meticulously devised a flow cell tailored for operando X-ray absorption spectroscopy (XAS) during CO 2 RR, accurately replicating the electrocatalytic conditions. 1 This innovative technique allows assessment of the authentic forms of the catalysts in diverse catalyst systems and facilitates the development of synthetic strategies aimed at achieving high catalytic activity. Fig. 1 : (a) Operando XANES and valence-state analyses for CuCO 3 and CuBaCNT during CO 2 RR. (b) Operando XANES and linear combination fitting for Cu 2 O(CO) at open- circuit potential (OCP) and 500 mA cm −2 during CO 2 RR. [Reproduced from Refs. 2 and 3] of the active species can be explored by operando APXPS measurements. This crucial information serves as a foundation for designing and optimizing electrocatalysts with better performance. (Reported by Chia-Hsin Wang) This report features the work of Chia-Hsin Wang and his collaborators published in ChemCatChem 15 , e202300359 (2023), and the work of Yu-Hsu Chang and his collaborators published in ACS Catal. 13 , 13434 (2023). TLS 24A1 XPS, UPS, XAS, APXPS • XPS, UPS, Ambient Pressure XPS • Materials Science References 1. C.-C. Yang, M.-H. Tsai, Z.-R. Yang, Y.-C. Tseng, C.-H. Wang, ChemCatChem 15 , e202300359 (2023). 2. P. Patta, Y.-Y. Chen, M. Natesan, C.-L. Sung, C.-C. Yang, C.-H. Wang, T. Fujigaya, Y.-H. Chang, ACS Catal. 13 , 13434 (2023). Operando X-ray Absorption Spectroscopic Studies within a Flow Cell for Carbon Dioxide Reduction Reaction Utilizing a flow cell can significantly boost the catalytic activities of the carbon dioxide reduction reaction. Employing an operando flow cell that mimics the catalytic environment allows for the investigation of the chemical and structural evolution in highly efficient catalysts.