Four Mo-based catalysts were prepared via three different synthesis techniques supported on SiO2 and/or SBA-15. By means of complementary in situ characterization techniques, the carburization process and the final characteristics of these catalysts were investigated. Additionally, the four catalysts were evaluated for the activation of CO2 in the absence and presence of H2 (reverse water–gas shift, RWGS). The results suggest that CO2 reacts via a dissociation on the carbide surface, forming adsorbed oxygen surface species. Severe oxidation of the carbide into its oxidic phases (MoO2 or MoO3) only occurs at temperatures above 850 K in the presence of CO2. O2 dissociates on the carbide surface when introduced at low concentrations (1 vol %) at room temperature, but when exposed to higher concentrations, a strong exothermic bulk re-oxidation reaction occurs, forming MoO2. All four catalysts show high RWGS activity in terms of CO2 conversions with a minimum CO selectivity of 98% without any signs of bulk catalyst oxidation. Although minimal, the observed deactivation is suggested to be primarily due to phase changes between Mo2C allotropes (β-phase, oxycarbide, and η-phase) and/or sintering of the active phase.

Potassium promoted β-Mo2C catalysts were studied in the hydrogenation of CO to oxygenates. The effect of synthesis procedures, promotion levels and reaction conditions on catalyst activity and selectivity was investigated in detail.

Mixed-metal cobalt oxide, namely cobalt aluminate and titanate, were shown to be water gas shift inactive.

The performance of Mo2C-based catalysts in CO2 assisted oxidative dehydrogenation of ethane (CO2-ODH) were evaluated. Mo2C on SiO2 was synthesized via three different techniques: wet impregnation (WI), hybrid nanocrsytal technique...