Mechanistic Insights into CO2 Methanation over Ru-Substituted CeO2

• DOI: 10.1021/acs.jpcc.6b03224
• Publication Date: 2016-06-14T08:12:34Z
• Authors: Sudhanshu Sharma; K. B. Sravan Kumar; Yash M. Chandnani; V. Sai Phani Kumar; Bhanu P. Gangwar; Aditi Singhal; Parag A. Deshpande
• Keywords: Methanation; Chemisorption; Stoichiometry

CO2 methanation is an important probe reaction to understand interactions with catalytic surfaces. The importance of this further increased by its association utilization. This study reports the mechanistic aspects over combustion synthesized Ru-substituted CeO2 catalyst. Temperature-programmed experiments were carried out interaction CO2, H2, and their stoichiometric mixture catalyst surface. In situ FTIR spectroscopy was used identify intermediates reaction. It observed that adsorption took place on surface Ce0.95Ru0.05O2 formation carbonate only when H2 present in gas phase. absence did not show any indication for chemisorption. behavior explained terms between hydroxyls leading a vacancy. Upon dissociation, carbonates led chemisorbed CO which eventually formed methane upon gas-phase H2. exact identity species pathway step ambiguous following purely experimental studies. Density functional theory calculations augment observations. Complete energy landscapes developed basis differentiation oxidized reduced forms showed followed consisting oxide CO, sequential via methoxy formation. provides physical insights into role oxidation state anionic vacancies governing pathway.