# Nanoscale Chemical Analysis of Heterogeneous Catalysts Using Tip-Enhanced Raman Spectroscopy

## TL;DR

This review discusses how tip-enhanced Raman spectroscopy can be used to study heterogeneous catalysts at the nanoscale, offering insights into their structure and function.

## Contribution

The paper provides a comprehensive review of TERS applications in heterogeneous catalysis, emphasizing its unique ability to probe nanoscale chemical processes.

## Key findings

- TERS enables nanoscale chemical analysis of catalytic surfaces with high spatial resolution.
- TERS can be applied in various environments including air, liquid, and electrochemical settings.
- The review highlights key mechanistic insights gained from TERS studies on catalytic systems.

## Abstract

Heterogeneous catalysts
underpin much of the modern chemical industry,
yet their rational design for enhanced activity, selectivity, and
sustainability remains a formidable challenge due to the intrinsic
structural and chemical heterogeneity of catalytic surfaces. Conventional
ensemble-averaged characterization techniques often fail to capture
the nanoscale complexity that governs catalytic function. Over the
past two decades, tip-enhanced Raman spectroscopy (TERS) has emerged
as a powerful nanoanalytical technique, offering single-molecule sensitivity
and spatial resolution down to the Ångström scale. In
this Review, we present TERS as a versatile, nondestructive, and label-free
approach for probing heterogeneous catalytic reactions with nanometer-scale
chemical specificity in air, liquid, and electrochemical environments.
We first introduce the fundamental principles and instrumental implementations
that underpin reliable TERS measurements. We then provide a comprehensive
and critical assessment of reported ex situ, in situ, and emerging operando TERS studies
across a wide range of catalytic systems, highlighting key mechanistic
insights uniquely accessible by this technique. Finally, we discuss
the technical challenges and methodological requirements for advancing operando TERS toward realistic reaction conditions, and
outline promising directions for future research. By integrating practical
considerations with conceptual advances, this Review aims to serve
as a comprehensive guide for researchers seeking to apply TERS to
nanoscale chemical analysis in heterogeneous catalysis.