Unveiling Atomic-restructuring of Cu-based Bimetallic Nanocatalysts for CO2RR using In-situ/operando Electrochemical Liquid Cell Electron Microscopy

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Haimei Zheng of the University of California, Berkeley is studying copper-based nanocatalysts for carbon dioxide (CO2) conversion to useful fuels and chemicals. Copper-based bimetallic nanocatalysts have gained significant attention for their potential to improve the process of CO2 transformation; however, these catalysts do not remain unchanged during reactions—their surfaces often shift away from their original structures. Understanding how and why these changes occur is essential, as they can greatly affect how well the catalyst performs and how long it remains effective. This project aims to uncover how copper-based bimetallic catalysts transform during CO2 conversion using a powerful technique called in-situ electrochemical liquid cell transmission electron microscopy (EC-TEM). This is currently the only method capable of directly observing such atomic-scale changes in real time. By watching these transformations as they happen, the research team hopes to uncover how changes in structure and chemical bonding influence catalytic performance. The knowledge gained could help scientists design better, more efficient catalysts for energy applications. Beyond its scientific goals, the project will also provide valuable training opportunities for both graduate and undergraduate students. It will help prepare the next generation of scientists and engineers while contributing to the long-term competitiveness of U.S. technology and innovation. With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Haimei Zheng of the University of California, Berkeley is studying copper-based bimetallic nanocatalysts for electrochemical carbon dioxide reduction (CO2RR), focusing on model systems such as CuM (M = Pd, Ag, etc.) to elucidate atomic-scale restructuring processes using in-situ EC-TEM. The research will involve fabricating advanced electrochemical liquid cells with precisely controlled potentials for high-resolution, real-time imaging; performing EC-TEM studies on well-defined CuM catalysts with varied structural configurations to capture atomic and morphological transformations during CO2RR; and conducting complementary multimodal characterizations across multiple length scales, including low-dose cryo-EM imaging and spectroscopy to resolve the atomic structure and chemical bonding of reaction intermediates, as well as operando X-ray absorption spectroscopy (XAS) to monitor valence state evolution in catalyst ensembles. In parallel, the project will integrate theoretical modeling and electrochemical performance testing through established collaborations to elucidate restructuring mechanisms and correlate surface structure with CO2RR activity and selectivity. Collectively, these efforts are expected to yield critical mechanistic insights into the dynamic behavior of bimetallic electrocatalysts, ultimately guiding the rational design of next-generation CO2RR catalysts with enhanced efficiency, durability, and product selectivity. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.