Adsorption and reaction mechanism of UDMH and O2 on Cu2O (111) surface: A combined first-principles and reactive molecular dynamics study

Abstract

Unsymmetrical dimethylhydrazine (UDMH), a widely used liquid propellant, has garnered significant attention for its environmental monitoring challenges. This study explores the adsorption properties and reaction mechanisms of UDMH and oxygen on the Cu₂O (111) surface through first-principles calculations and molecular dynamics simulations. Initially, adsorption energies and charge transfer dynamics were analyzed at various adsorption sites, revealing strong adsorption capacities for both UDMH and oxygen. Subsequently, molecular dynamics simulations elucidated the reaction pathways between UDMH and oxygen on the Cu₂O (111) surface. The results indicate that UDMH undergoes rapid redox reactions with oxygen, forming multiple stable compounds. This highlights the substantial impact of oxygen on the accuracy of UDMH concentration detection by Cu₂O-based sensors. These findings provide valuable insights for improving the design and functionality of gas-sensitive materials for UDMH detection.