Activity and stability assessment of Pt/C and FeNC catalysts through a channel flow cell

• Modular CFC development for operando electrocatalyst stability assessment. • CFC reproduces RDE/MEA trends in ECSA loss. • Online CFC-ICP-MS tracks real-time dissolution (Pt, Fe) up to 80°C. We present a modular channel flow cell (CFC) platform integrated with online inductively coupled plasma mass spectrometry (ICP-MS) for real-time, temperature-resolved assessment of electrocatalyst stability. The system enables precise control of laminar flow, mass transport while also facilitating accurate kinetic and intrinsic degradation analyses. Using Pt/C and FeNC catalysts, we demonstrate the platform’s capability to quantify electrochemical surface area (ECSA) loss and metal dissolution under accelerated stress testing at both room temperature and 80 °C. Importantly, the CFC reliably reproduces degradation trends observed in rotating disk electrode (RDE) and membrane electrode assembly (MEA) setups, validating its predictive relevance. Operando ICP-MS measurements reveal temperature-enhanced dissolution of Pt and Fe, with Fe dissolution notably suppressed under oxygen due to reprecipitation phenomena. This study establishes the CFC–ICP-MS system as a robust tool bridging laboratory screening and device-level durability evaluation for fuel cell and electrolyser catalysts.