• Citer

XPS as a probe of the chemical state of Cu during thermal decomposition of copper oxalate in hydrogen

par Chenakin, Sergiy ;Kruse, Norbert
Référence Applied surface science, 716, 164671
Publication Publié, 2026-01

Article révisé par les pairs

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

X-ray photoelectron spectroscopy was employed to study the thermal decomposition of Cu oxalate hydrate, CuC2O4·0.31H2O, under hydrogen environmental conditions. Analysis of the parameters of Cu 2p, Cu L3VV, C 1 s, O 1 s and valence band high-resolution XP spectra showed that the structure, composition and chemical state of copper atoms continuously change with increasing temperature. After dehydration of the sample, the nucleation and accumulation of Cu2O and Cu phases along with the deterioration of the residuary oxalate structure was revealed to occur in the temperature range of ∼230–260 °C. The simultaneous existence of all three chemical states, Cu2+, Cu1+ and Cu0, in the decomposing material indicated two reaction pathways for the decomposition of oxalate to be in operation. In this range of temperatures, the amount of Cu2O increased slowly and non– monotonically, peaking at 250 °C, whereas the amount of Cu increased monotonically, remaining below that of Cu2O up to 250 °C, before snowballing due to the rapid disintegration of the oxalate structure to form metallic Cu at 280 °C. The surface of the final product was found to be covered with various adsorbed oxygen-containing carbon functional groups formed because of various reactions, including hydrogenation of the evolving CO2 catalyzed by active Cu nanoparticles. A comparison of the changes in the Cu oxalate state under heating and prolonged X-ray irradiation was performed. The XPS studies were complemented by XRD, TG, and TPDec coupled with quadrupole mass spectrometry.