Methane activation on metal oxide nanoparticles: spectroscopic identification of reaction mechanism

Abstract

Currently, there is a lack of detailed knowledge about methane (CH₄) reactions on metal oxide surfaces. This reaction involves in different processes such as chemical looping combustion and catalytic carbon dioxide (CO₂) reforming of CH₄. In this study, in situ diffuse reflectance infrared Fourier transform spectroscopy was used to investigate CH₄ reaction on three transition metal oxides (CoO, CuO, and α-Fe₂O₃) which are commonly used in these processes at temperatures ranging from 100 °C to 700 °C. The results show that CH₄ is adsorbed on the metal oxide surfaces as methoxy and formate, and then the methoxy group reacts with the metal oxide lattice oxygen forming bicarbonate. Under the effect of the used reaction temperature, the bicarbonate decomposes to CO₂ and water vapor.

Keywords:

• Reduction mechanism
• CoO
• hematite
• CuO
• CLC
• CH₄ Reforming to CO₂

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Dr. Hayder Alalwan would like to thanks the support from The Middle Technical University. The authors would like to acknowledge the support from Al-Mustaqbal University College through the fund MUC-E-0122.