# Recent Advances in Mediator and Proton Relay Usage in Molecular Catalysis

## TL;DR

This paper reviews recent advances in using mediators and proton relays to improve molecular catalysts for energy-related reactions.

## Contribution

The paper systematically benchmarks the use of EPTMs, RMs, and PRs in molecular catalysis using kinetic and thermodynamic analyses.

## Key findings

- EPTMs, RMs, and PRs enhance catalytic efficiency in reactions involving CO2, O2, H2O, and N2.
- Linear free energy relationships and catalytic Tafel plots provide insights into reaction mechanisms and selectivity.
- The review offers a foundation for the rational design of molecular catalysts for energy conversion.

## Abstract

Electron–proton transfer mediators (EPTMs), redox mediators (RMs), and proton relays (PRs) have been incorporated into diverse homogeneous molecular catalysts to enhance catalytic efficiencies in the reactions of energy‐related small molecules (e.g., CO2, O2,H2O, and N2) and organic compounds. However, the benefits of using EPTMs, RMs, and PRs in molecular catalysis have not been comprehensively or quantitatively benchmarked. This review highlights the latest developments in this field, focusing on the kinetics, thermodynamics, and selectivities of multiple proton–electron redox processes, as well as their corresponding advantages. The reaction mechanisms, linear free energy relationships, and catalytic Tafel plots are considered to provide a solid foundation for evaluating these catalytic systems and the strategic development of molecular catalysts. These efforts are expected to advance the application of molecular catalysis in energy conversion and sustainability.

The use of electron–proton transfer mediators, redox mediators, and proton relays in synergy with molecular catalysts in energy‐related small‐molecule and organic transformations is discussed, with a focus on recent advances. Linear free‐energy relationship and catalytic Tafel plots provide a systematic foundation for benchmarking these catalytic systems and the rational design of molecular catalysts.