Dynamic Response Spectroscopy: An Emergentist Framework for Multi-Timescale Catalytic Interfacial Dynamics.

Area of Science:

• Surface Science and Catalysis
• Electrochemical Interfaces
• Spectroscopic Methods

Background:

• Catalytic interfaces exhibit complex, multi-timescale dynamics involving ions, solvents, and adsorbates.
• Classical electrochemical models often treat interfaces as static, limiting understanding of dynamic contributions to catalysis.
• Existing spectroscopic probes frequently assume linearity or time-invariance, hindering resolution of intricate interfacial processes.

Purpose of the Study:

• To formalize and expand Dynamic Response Spectroscopy (DRS) for disentangling nonlinear interfacial dynamics.
• To develop a generalized simulation approach for modeling spectrotemporal responses to modulation.
• To demonstrate DRS's capability in resolving complex dynamics beyond traditional analyses.

Main Methods:

• Leveraging temporally structured perturbations and time-resolved spectroscopic detection.
• Developing a generalized simulation framework to model spectrotemporal responses.
• Applying DRS to synthetic systems and experimental operando ATR-SEIRAS during CO2 electroreduction on copper.

Main Results:

• DRS successfully disentangles overlapping and coupled nonlinear interfacial dynamics, including non-Faradaic processes.
• Simulations enable systematic evaluation of component retrievability across different coupling topologies and kinetic regimes.
• DRS uncovered solvent dynamics, charging delays, and memory effects missed by conventional methods in CO2 electroreduction.

Conclusions:

• DRS provides a powerful framework applicable to diverse catalytic systems with complex interfacial dynamics.
• The method allows the system's natural dynamical structure to emerge, reducing reliance on predefined mechanistic assumptions.
• DRS offers a novel approach for mechanistic insight into catalytic activity, selectivity, and stability by addressing time-domain complexity.