# Stable Tetravalent Metal–Organic Frameworks for Electrocatalysis and Aqueous Electrochemical Energy Storage

## TL;DR

This paper reviews tetravalent metal-based MOFs and their use in electrocatalysis and energy storage in aqueous environments.

## Contribution

The paper provides a comprehensive overview of the progress and potential of tetravalent metal-based MOFs in aqueous electrochemical applications.

## Key findings

- Tetravalent metal-based MOFs show high stability and tunability for aqueous electrochemical applications.
- These MOFs are used in water splitting, oxygen reduction, and energy storage systems like supercapacitors and batteries.

## Abstract

Owing to their chemical
stability in water, relatively
high specific
surface area, and high tunability in both pore structures and chemical
functionality in their pores, metal–organic frameworks (MOFs)
constructed from tetravalent metal-based nodes, including zirconium-based
MOFs, titanium-based MOFs, hafnium-based MOFs, cerium­(IV)-based MOFs
and thorium-based MOFs, have been widely explored for various applications
requiring humid or aqueous environments. In particular, over the past
ten years, these MOFs have been widely employed in various aqueous
electrochemical applications, including water splitting, oxygen reduction,
carbon dioxide reduction, ammonia production, electrocatalytic sensing,
aqueous supercapacitors, zinc-ion batteries, and vanadium flow batteries.
Classified by the type of applications and the role that MOFs could
play, progress in this research field is overviewed. Limitations and
opportunities in this field for future studies are discussed.