Electrochemical Scanning Tunneling Microscopy in Electrocatalysis

Electrochemical scanning tunnelling microscopy (EC-STM) combines the sub-nanometre spatial resolution of scanning tunnelling microscopy with the ability to control and monitor electrode potential in liquid environments. By positioning an ultrafine conductive tip within angstroms of an electrocatalyst surface immersed in electrolyte, EC-STM can visualise surface atomic arrangements, dynamic reconstructions and the adsorption of reactant species under operando conditions. This technique has transformed our understanding of electrocatalytic processes—such as oxygen reduction, hydrogen evolution and CO₂ reduction—by revealing the nature and distribution of active sites, the evolution of surface morphology and the pathways of electron-transfer mechanisms. Recent enhancements include high-speed imaging, combined force-sensing probes and advanced tip-coating methods to suppress faradaic currents, opening new avenues for real-time studies of catalyst degradation, phase transitions and single-molecule catalysis. These insights are guiding the rational design of next-generation energy conversion materials.

Research from Nature Portfolio

Enzyme‐inspired metal–organic networks self‐assembled on Au(111) have been shown to mimic the coordination environment of natural active centres, achieving efficient oxygen reduction in alkaline media. Atomically precise two-dimensional networks incorporating single iron and manganese atoms exhibit distinct catalytic behaviour and selectivity, demonstrating that surface-engineered coordination complexes can serve as a new class of nanocatalysts. A foundational study further established that embedding earth-abundant metal centres within organic ligands at electrified interfaces yields stable, high-activity sites, paving the way for surface-driven electrocatalytic conversions.

Electrochemical Scanning Tunneling Microscopy in Electrocatalysis publication trend

The graph below shows the total number of articles in electrochemical scanning tunneling microscopy in electrocatalysis across all publications each year (not limited to Nature Index journals).

Technical terms

Electrochemical scanning tunnelling microscopy (EC-STM): A technique that images electrode surfaces at atomic resolution under controlled electrochemical potential in liquid environments.

Outer-sphere electron transfer: A reaction mechanism in which electrons move between electrode and reactant without formation of a chemical bond to the surface.

Turnover frequency (TOF): A measure of catalytic activity defined as the number of reactant molecules converted per active site per unit time.

Single-site catalyst: A catalyst in which isolated active metal centres are uniformly dispersed on a support, enabling precise structure–activity correlations.

Active site: The specific atomic or molecular location on a catalyst surface where reactant conversion occurs.

References

1. Application of Scanning Tunneling Microscopy in Electrocatalysis and Electrochemistry. Electrochemical Energy Reviews (2021).
2. Combining Electrochemical Scanning Tunneling Microscopy with Force Microscopy. ACS Nano (2025).
3. Highly Reproducible Automated Tip Coater for In Situ and Operando EC-STM Measurements. Surfaces (2024).
4. Bio-inspired nanocatalysts for the oxygen reduction reaction. Nature Communications (2013).
5. Molecular Self-Assembly at Metal-Electrolyte Interfaces. International Journal of Molecular Sciences (2013).
6. Free‐Base Octaethylporphyrin on Au(111) as Heterogeneous Organic Molecular Electrocatalyst for Oxygen Reduction Reaction in Acid Media: An Electrochemical Scanning Tunneling Microscopy and Rotating Ring‐Disc Electrode Analyses. Small Science (2024).
7. Electrochemical Scanning Tunneling Microscopy as a Tool for the Detection of Active Electrocatalytic Sites. Topics in Catalysis (2023).
8. In Situ Quantification of the Local Electrocatalytic Activity via Electrochemical Scanning Tunneling Microscopy. Small Methods (2020).