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

Muhamed Yusuf Shahul Hamid; Sugeng Triwahyono; Aishah Abdul Jalil; Nurfatehah Wahyuny Che Jusoh; Siti Maryam Izan; Tuan Amran Tuan Abdullah

doi:10.1021/acs.inorgchem.8b00241

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

Inorg Chem. 2018 May 21;57(10):5859-5869. doi: 10.1021/acs.inorgchem.8b00241. Epub 2018 May 10.

Authors

Muhamed Yusuf Shahul Hamid¹, Sugeng Triwahyono², Aishah Abdul Jalil^{1

3}, Nurfatehah Wahyuny Che Jusoh⁴, Siti Maryam Izan², Tuan Amran Tuan Abdullah^{1

3}

Affiliations

¹ Department of Chemical Engineering, Faculty of Chemical Engineering , Universiti Teknologi Malaysia , 81310 UTM Johor Bahru , Johor , Malaysia.
² Department of Chemistry, Faculty of Science , Universiti Teknologi Malaysia , 81310 UTM Johor Bahru , Johor , Malaysia.
³ Center of Hydrogen Energy, Institute of Future Energy , Universiti Teknologi Malaysia , 81310 UTM Johor Bahru , Johor , Malaysia.
⁴ Department of Chemical Process Engineering, Malaysia-Japan International Institute of Technology (MJIIT) , Universiti Teknologi Malaysia Kuala Lumpur , Jalan Sultan Yahya Petra , 54100 Kuala Lumpur , Malaysia.

PMID: 29746104
DOI: 10.1021/acs.inorgchem.8b00241

Abstract

Nickel (Ni), cobalt (Co), and zinc (Zn) loaded on fibrous silica KCC-1 was investigated for CO₂ methanation reactions. Ni/KCC-1 exhibits the highest catalyst performance with a CH₄ formation rate of 33.02 × 10^-2 mol_CH4 mol_metal^-1 s^-1, 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 N₂ 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 CO₂ methanation. It was discovered that Ni/KCC-1 and Co/KCC-1 follow a dissociative mechanism of CO₂ methanation in which the CO₂ 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_ads) 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 CO₂ to form CO_ads and OH. These results offers a better understanding for catalytic studies, particularly in the field of CO₂ recycling.