Metrohm Hyphenated EC-Raman for electrocatalysis

Significance of the Topic

Understanding electrocatalysts under working conditions is critical for advancing energy conversion and storage technologies. By coupling electrochemical control with Raman spectroscopy, researchers can observe structural changes, intermediate species and reaction pathways in real time, improving catalyst design and performance.

Study Objectives and Overview

This work presents two turnkey EC-Raman solutions tailored for electrocatalysis research: the Explorer and the Starter systems. Both integrate a potentiostat/galvanostat from Metrohm Autolab with a B&W Tek Raman spectrometer, synchronized via a trigger cable and controlled in a unified software environment. These packages aim to simplify operando measurements without complex setups or extensive training.

Instrumentation Used

• Autolab PGSTAT302N with EIS module (±10 V, ±30 V compliance, 10 nA–1 A current range, 1 MHz bandwidth)
• Autolab PGSTAT204 with EIS module (±10 V, ±20 V compliance, 10 nA–100 mA, 1 MHz bandwidth)
• B&W Tek i-Raman Plus 532H (532 nm laser, 30 mW, CCD cooled to –2 °C, 65–3400 cm⁻¹ range, <3.5 cm⁻¹ resolution)
• B&W Tek BAC151 Raman Video Microsampling System (532 nm, video camera with coaxial LED, 20× & 50× objectives)
• Trigger cable for synchronization and NOVA software integration

Methodology and Techniques

The systems perform operando measurements by triggering Raman spectra acquisition at defined electrochemical potentials or during impedance scans. Key techniques include:

• Electrochemical Impedance Spectroscopy for monitoring adsorption and interfacial properties
• Surface‐Enhanced Raman Spectroscopy for signal enhancement on nanostructured electrodes
• Raman Microscopy for spatially resolved chemical mapping

Main Results and Discussion

Both configurations enable precise alignment of the Raman probe and electrode, ensuring reproducible data collection. The modular PGSTAT302N allows future expansion with bipotentiostat, low‐current amplifiers and fast scan generators. The portable PGSTAT204 in the Starter kit facilitates on-site experiments. Users achieved stable signal synchronization, high spectral resolution and broad dynamic ranges, demonstrating the systems versatility for studying molecular catalysts, metal oxides, carbon materials and transition metal dichalcogenides.

Benefits and Practical Applications

• Rapid deployment and minimal training requirements
• High accuracy EIS and Raman data in a single platform
• Operando insight into reaction intermediates and catalyst stability
• Scalable hardware for evolving research needs

Future Trends and Opportunities

Advances may include integration with microfluidic cells, automated data analysis via machine learning, multi-technique hyphenation (e.g. UV-Vis or IR spectroscopy) and deployment in industrial process monitoring. Customized cell designs will enable studies under higher pressures, temperatures or flow conditions, broadening the scope of electrocatalysis investigations.

Conclusion

Metrohm’s hyphenated EC-Raman solutions offer a streamlined approach to operando electrocatalysis, merging sophisticated electrochemical control with high-resolution molecular characterization. These systems accelerate discovery and optimization of catalysts for energy and environmental applications.