Tailoring the Properties of Metal Oxide Loaded/KCC-1 toward a Different Mechanism of CO₂ Methanation by in Situ IR and ESR

Abstract

Nickel (Ni), cobalt (Co), and zinc (Zn) loaded on fibrous silica KCC-1 was investigated for CO methanation reactions. Ni/KCC-1 exhibits the highest catalyst performance with a CH formation rate of 33.02 × 10 mol mol s, 1.77 times higher than that of Co/KCC-1 followed by Zn/KCC-1 and finally the parent KCC-1. A pyrrole adsorption FTIR study reveals shifting of perturbed N-H stretching decreasing slightly with the addition of metal oxide, suggesting that the basic sites of catalyst were inaccessible due to metal oxide deposition. The strengths of basicity were found to follow sthe equence KCC-1, Ni/KCC-1, Zn/KCC-1, and Co/KCC-1. The data were supported by N adsorption desorption analysis, where Co/KCC-1 displayed the greatest reduction in total surface area whereas Ni/KCC-1 displayed the least reduction. The elucidation of difference mechanism pathways has also been studied by in situ IR spectroscopy studies to determine the role of different metal oxides in CO methanation. It was discovered that Ni/KCC-1 and Co/KCC-1 follow a dissociative mechanism of CO methanation in which the CO molecule was dissociated on the surface of the metal oxide before migration onto the catalyst surface. This was confirmed by the evolution of a peak corresponding to carbonyl species (CO) on a metal oxide surface in FTIR spectra. Zn/KCC-1, on the other hand, showed no such peak, indicating associative methanation pathways where a hydrogen molecule interacts with an O atom in CO to form CO and OH. These results offers a better understanding for catalytic studies, particularly in the field of CO recycling.

Boosting Ni Dispersion on Zeolite-Supported Catalysts for CO2 Methanation: The Influence of the Impregnation Solvent

“…Finally, in order to further evaluate the relevance of the catalytic performances exhibited by the catalysts studied on this work, CH 4 production rates of the best catalytic system (15Ni/Cs-USY 2‑PrOH ) at 200–350 °C were compared to those obtained for 10–20 wt % Ni-supported catalytic systems applied in CO 2 methanation in the literature and also with a sponge Ni with >92.5 wt % Ni (Figure ). As verified, Ni/Cs-USY 2‑PrOH led to similar or better performances than other Ni-supported zeolites (Cs-MOR and Cs-ZSM-5), mesoporous silicas (KCC-1, SBA-15, and MCM-41), , γ-Al 2 O 3 -ZrO 2 -TiO 2 -CeO 2 composites, Al 2 O 3 , ZrO 2 , Y-ZrO 2 , Ce-Zr, , MOF-5, or even sponge Ni . This observation clearly evidences the relevance of these materials for the CO 2 methanation reaction and motivates further improvements towards its industrial application.…”

Dendritic Mesoporous Nanoparticles: Structure, Synthesis and Properties

“…In addition to drug delivery, flower‐like DMSNs can be further functionalized for catalysis, phototherapy, and other applications. DMSNs have been incorporated with gold, [103, 112, 113] silver, [114] iron oxide, [103, 115, 116] quantum dots, [117, 118] upconversion NPs, [119] tantalum, [120] palladium, [121] ruthenium, [122–124] nickel, cobalt and zinc oxides, [125] vanadium, [126] and calcium [127] as well as multiple nanoparticles/elements [117] . For example, Gao et al.…”

Synthesis of lanthanide series (La, Ce, Pr, Eu & Gd) promoted Ni/γ-Al2O3 catalysts for methanation of CO2 at low temperature under atmospheric pressure

“…El segundo posible mecanismo describe una adsorción disociativa de CO2 en COad y Oad como los principales intermediarios de esta ruta de metanación (ver Figura 5) y cuya activación se da sobre la partícula metálica, luego prosigue la reacción disociativa a Cad y Oad, hasta su posterior hidrogenación a CH4 y H2O [56,58,60], siendo una reacción análoga a la hidrogenación de CO.…”