# Engineering MXenes for Thermal and Photothermal Catalysis

## TL;DR

This review discusses how MXenes, a class of two-dimensional materials, are engineered for use in thermal and photothermal catalysis, highlighting their structural features and catalytic performance.

## Contribution

The paper provides a focused review on MXenes for thermal and photothermal catalysis, emphasizing synthesis, active site characterization, and reproducibility.

## Key findings

- MXenes offer high atom utilization due to their two-dimensional structure and exposed atoms.
- Surface groups, vacancies, and metal–support interfaces significantly influence catalytic activity.
- MXenes exhibit high light-to-heat conversion efficiency in photothermal reactions.

## Abstract

Heterogeneous catalysis relies on advanced, tunable materials
offering
structurally defined active sites and large accessible surface areas.
Among the various material types, two-dimensional nanomaterials with
high aspect ratios feature a high fraction of exposed atoms and thus
efficient atom utilization. After more than a decade since the first
report of MXene synthesis, these two-dimensional transition-metal
carbides and nitrides, composed of alternating one-atom-thick metal
and carbide/nitride layers with surface terminations, have found applications
in diverse catalytic areas. This review focuses on the use of MXenes
as solid catalysts in thermal or photothermal reactions, while electro-
and photocatalysis are excluded as they have been extensively reviewed
elsewhere. Section 2 briefly summarizes MXene synthesis and structural
features, followed by Section 3 describing the nature and characterization
of catalytically active sites, including surface groups, vacancies,
and metal–support interfaces that arise from the synthesis
conditions. Section 4 emphasizes best practices for ensuring reproducible
and stable catalytic performance, with turnover frequency as a key
comparative metric. Sections 5 and 6 highlight some representative
thermal and photothermal reactions, underscoring the high light-to-heat
conversion efficiency of MXenes. This review concludes with current
challenges and future prospects, anticipating rapid progress with
MXene-based heterogeneous catalysis.