Decomposition process of copper(ii) formate tetrahydrate through molecular dynamics simulations

The thermal decomposition of Cu(ii) formate tetrahydrate into metallic Cu is a multi-stage process critical to the development of particle-free conductive inks. This work correlates macroscopic thermal behavior with atomic-scale transformations by integrating physicochemical analyses with reactive molecular dynamics simulations. Differential scanning calorimetry reveals three distinct dehydration peaks at 52 °C, 80 °C and 102 °C followed by a final decomposition at 217 °C that reduces Cu formate into metallic Cu. Simulations use reactive force field (ReaxFF) to track step-wise dehydration and associated charge distribution dynamics. The simulations demonstrate that the loss of the first three hydration water molecules occurs from the outer lattice, leaving the Cu²⁺ coordination sphere intact. However, at 217 °C, the release of the final, strongly bound water molecule destabilizes the formate-copper interactions, acting as a stoichiometric structural trigger for the reduction process to Cu⁰. These findings offer frameworks to model decomposition kinetics in Cu complexes and optimize the corresponding inks for applications in flexible printed electronics.