Improved Electron Imaging of Cu Nanocatalyst Evolution at Realistic CO2 Electroreduction Conditions

作者：Saltanat Toleukhanova, Vasiliki Tileli · 发表于：Microscopy and Microanalysis · 年份：2025 · DOI：10.1093/mam/ozaf048.658 · 被引用次数：1 · 研究领域：CO2 Reduction Techniques and Catalysts、Electrochemical Analysis and Applications、Electrocatalysts for Energy Conversion

Structural and morphological degradation of Cu-based catalysts during the CO2 electroreduction reaction (CO2ER) inhibits the efficient conversion of CO2 into high-energy-density fuels [1]. Electrochemical liquid-phase electron microscopy (ec-LPEM) has been fruitfully applied to monitor catalyst degradation in real time, providing a deeper understanding of the restructuring pathways [2, 3]. Nevertheless, the limited spatial resolution in liquids and substrate electrode stability hinder the precise observation of the catalyst-liquid interface. In this regard, graphene has been shown to be a promising electrode material in ec-LPEM studies [4]. Herein, we have employed free-standing graphene as both membrane and electrode material, with the aim of improving the spatial resolution and expanding the potential stability window in ec-LPEM studies of energy materials, and in particular Cu-based nanocatalysts [5]. Experiments were performed using an electrochemical scanning electron microscopy (SEM) stage equipped with bulk reference and counter electrodes. The electrochemical graphene chip (Fig.1a,b) was microfabricated by patterning a single Pt electrical pad on a Si/SiNx chip with a 50 nm thick SiNx electron-transparent membrane. An array of holes in the SiNx membrane was perforated using reactive ion etching. The strengthening of graphene’s mechanical properties was achieved by stacking three layers of monolayer graphene (Fig.1c,d) using a PMMA-assisted wet transfer method. The res...