Yoon Aram, Bai Lichen, Yang Fengli, Franco Federico, Zhan Chao, Rüscher Martina, Timoshenko Janis, Pratsch Christoph, Werner Stephan, Jeon Hyo Sang, Monteiro Mariana Cecilio de Oliveira, Chee See Wee, Roldan Cuenya Beatriz
Department of Interface Science, Fritz-Haber Institute of the Max-Planck Society, Berlin, Germany.
Shell Global Energy Solution International BV, Amsterdam, Netherlands.
Nat Mater. 2025 May;24(5):762-769. doi: 10.1038/s41563-024-02084-8. Epub 2025 Jan 24.
Electrocatalysts alter their structure and composition during reaction, which can in turn create new active/selective phases. Identifying these changes is crucial for determining how morphology controls catalytic properties but the mechanisms by which operating conditions shape the catalyst's working state are not yet fully understood. In this study, we show using correlated operando microscopy and spectroscopy that as well-defined CuO cubes evolve under electrochemical nitrate reduction reaction conditions, distinct catalyst motifs are formed depending on the applied potential and the chemical environment. By further matching the timescales of morphological changes observed via electrochemical liquid cell transmission electron microscopy with time-resolved chemical state information obtained from operando transmission soft X-ray microscopy, hard X-ray absorption spectroscopy and Raman spectroscopy, we reveal that CuO can be kinetically stabilized alongside metallic copper for extended durations under moderately reductive conditions due to surface hydroxide formation. Finally, we rationalize how the interaction between the electrolyte and the catalyst influences the ammonia selectivity.
电催化剂在反应过程中会改变其结构和组成，这反过来又会产生新的活性/选择性相。识别这些变化对于确定形态如何控制催化性能至关重要，但操作条件塑造催化剂工作状态的机制尚未完全了解。在本研究中，我们使用相关的原位显微镜和光谱学表明，在电化学硝酸盐还原反应条件下，随着定义明确的CuO立方体的演变，根据施加的电势和化学环境会形成不同的催化剂图案。通过进一步将通过电化学液体池透射电子显微镜观察到的形态变化的时间尺度与从原位透射软X射线显微镜、硬X射线吸收光谱和拉曼光谱获得的时间分辨化学状态信息相匹配，我们发现由于表面形成氢氧化物，在适度还原条件下，CuO可以与金属铜一起在较长时间内动力学稳定。最后，我们阐述了电解质与催化剂之间的相互作用如何影响氨的选择性。
