Metrohm Hyphenated EC-Raman solutions for corrosion

Significance of the Topic

Corrosion control is vital across industries such as petrochemicals, infrastructure, and transportation. Monitoring degradation mechanisms in real time enhances material longevity, reduces maintenance costs, and improves safety. Hyphenated electrochemical and Raman spectroscopy techniques provide complementary insights into both chemical transformations and electrochemical behavior during corrosion processes.

Study Objectives and Overview

This application note presents two turnkey solutions from Metrohm for in situ corrosion research: the EC-Raman Explorer and EC-Raman Starter packages. Both systems synchronize potentiostatic or galvanostatic measurements with Raman spectral acquisition to deliver simultaneous structural and functional information. The goal is to offer ready-to-use setups requiring minimal training or complex synchronization.

Methodology and Used Instrumentation

Both solutions integrate electrochemical workstations (Autolab potentiostat/galvanostat with EIS capability) and fiber-optic Raman systems (B&W Tek). The key components include:

• Autolab PGSTAT302N with EIS module (Explorer): high compliance potentiostat/galvanostat, current ranges 10 nA–1 A, EIS 10 µHz–1 MHz
• Autolab PGSTAT204 with EIS module (Starter): compact potentiostat/galvanostat, current ranges 10 nA–100 mA, EIS 10 µHz–1 MHz
• B&W Tek i-Raman Plus 532H: 532 nm laser, 30 mW, spectral range 65–3400 cm⁻¹, <3.5 cm⁻¹ resolution
• B&W Tek BAC151 Video Microsampling System: fiber-optic probe, video camera for alignment, objectives 20× and 50×, XYZ translation stages

Synchronized control is achieved through a trigger cable and Metrohm’s NOVA software with built-in EC-Raman sequences. Data analysis can be extended in BWSpec.

Main Results and Discussion

The EC-Raman setup enables real-time correlation of electrochemical signals (e.g., impedance spectra, linear sweep voltammetry) with molecular fingerprint data from Raman spectroscopy. This dual perspective uncovers the onset of localized corrosion, coating degradation pathways, and adsorption behavior of inhibitors. Field-adjustable cells and optional modules—such as electrochemical noise (ECN), ultra-low-current amplifiers (1 nA and 100 pA ranges), and pX1000 sensors for voltage, temperature, and pH—further enhance adaptability to specific experimental needs.

Benefits and Practical Applications

• Non-invasive, in situ monitoring combining structural and functional insights
• Modular hardware allows incremental upgrades without full system replacement
• Preprogrammed software procedures reduce setup time and training effort
• Applicable to coatings evaluation, additive adsorption studies, localized corrosion analysis, and SERS for trace detection

Future Trends and Potential Applications

As corrosion research advances, integrating machine-learning algorithms with EC-Raman datasets will enable automated identification of corrosion markers and predictive maintenance schedules. Miniaturized electrochemical-Raman probes and flow-cell adaptations will extend applicability to on-line process monitoring in harsh environments. Further expansion into high-throughput screening could accelerate material development and inhibitor discovery.

Conclusion

Metrohm’s hyphenated EC-Raman solutions deliver a versatile, upgradeable platform for comprehensive corrosion research. By synchronizing electrochemical measurements and Raman spectroscopy within a single workflow, researchers gain unprecedented insights into degradation mechanisms and inhibitor performance. The ready-to-use Explorer and Starter packages simplify adoption, while modular add-ons future-proof experimental capabilities.