# Decomposition Process of Carboxylate MOF HKUST-1 Unveiled at the Atomic Scale Level

**Authors:** Michela Todaro, Gianpiero Buscarino, Luisa Sciortino, Antonino Alessi, Fabrizio Messina, Marco Taddei, Marco Ranocchiari, Marco Cannas, Franco M. Gelardi  
**arXiv:** [1704.01008](https://arxiv.org/abs/1704.01008)  
**Date:** 2017-03-31  
**Summary page:** https://www.summarizepaper.com/en/paper/1704.01008v1/

## Key points

- HKUST-1 is a metal-organic framework (MOF) with exceptional adsorption and catalytic properties.
- The paddle-wheel unit, which is the heart of the material, is prone to hydrolysis when exposed to moisture.
- An innovative approach combining electron paramagnetic resonance spectroscopy with other techniques was used to investigate this process at an atomic scale level.
- Three stages of decomposition were identified and corresponding equilibrium structures of the paddle-wheels were uncovered.
- This study sheds light on how HKUST-1 behaves under different environmental conditions and provides valuable information for future research on MOFs.

## Summary

HKUST-1 is a highly versatile metal-organic framework (MOF) that has garnered considerable attention in both basic and applied research due to its exceptional adsorption and catalytic properties. However, previous studies have demonstrated that the paddle-wheel unit - which comprises a pair of Cu2+ ions chelated by four carboxylate bridges and is the heart of the material - is prone to hydrolysis. Prolonged exposure to moisture can promote the hydrolysis of Cu-O bonds in the paddle-wheels, resulting in the breakdown of the crystalline network. To investigate this process at an atomic scale level, an innovative approach combining electron paramagnetic resonance spectroscopy with other commonly used techniques such as X-ray diffraction, surface area estimation, and scanning electron microscopy was employed. The main objective was to determine details about the decomposition process of HKUST-1 and uncover corresponding equilibrium structures of the paddle-wheels. This investigation successfully identified three stages of decomposition and provided insights into how these defects manifest at an atomic scale level. Overall, this study sheds light on how HKUST-1 behaves under different environmental conditions and provides valuable information for future research on MOFs.