dc.contributor.author	Sidik, Siti Munirah
dc.date.accessioned	2024-07-14T01:28:53Z
dc.date.available	2024-07-14T01:28:53Z
dc.date.issued	2016
dc.description	Thesis (PhD. (Chemical Engineering))
dc.description.abstract	Carbon dioxide (CO2) reforming of methane (CH4) is a promising technique in environment protection and future energy supply, due to its benefit of converting two major greenhouse gases (CH4 and CO2) into a valuable synthesis gas (hydrogen and carbon monoxide). In this study, mesostructured silica nanoparticle (MSN) and Mobil composition of matter number 41 (MCM-41) were selected as the support material due to their mesoporous structure and high surface area. The promotion of nickel (Ni) on MSN (Ni/MSN) and MCM-41 (Ni/MCM-41) was carried out using in-situ electrolysis. Besides, a series of Ni/MSN catalysts were prepared by different Ni-loading methods, including in-situ electrolysis (Ni/MSN_IS), impregnation (Ni/MSN_IM) and physical mixing (Ni/MSN_PM). In addition, the cobalt (Co) binder was added to the Ni/MSN using consecutive in-situ electrolysis. The catalysts were characterized using X-ray diffraction, nitrogen physisorption, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, CO adsorbed infrared (IR), pyrrole adsorbed IR, CO2 adsorbed IR, nuclear magnetic resonance, H2-temperature programmed reduction, electronic spin resonance and X-ray photoelectron spectroscopy analyses. The effects of supports, Ni-loading methods and Co binder addition towards the activity and stability of the Ni based catalysts were investigated in CO2 reforming of CH4. From the results, Ni/MSN exhibited a higher activity compared to the Ni/MCM-41 due to the presence of highly reducible Ni particle located on the surface of MSN and greater basicity in the catalyst, attributed to the presence of the interparticles voids in the MSN. The CH4 and CO2 conversions of Ni/MSN catalysts prepared by different Ni-loading methods are in the order of Ni/MSN_IM (CH4=45.6 %, CO2=52.4 %) < Ni/MSN_PM (CH4=60.5 %, CO2=83.9 %) < Ni/MSN_IS (CH4=94.3 %, CO2=91.7 %). The highest catalytic activity for Ni/MSN_IS was related to small and highly dispersed Ni particles, as well as high basicity and number of the surface defects. The addition of Co binder increased the activity of the Ni/MSN, resulted from the synergistic effect between Ni and Co in the Ni-Co solid solution. Based on the response surface methodology experiments, 96.3 % of CH4 conversion was achieved at the optimum conditions of 924 °C, CO2:CH4 ratio of 4.68, and gas hourly space velocity of 36,847 mLg-1h-1. Among the catalysts, Ni/MSN_IS and Ni-Co/MSN exhibited stable activity for more than 200 h time on stream. However, a lower metal sintering and carbon content was detected for Ni-Co/MSN due to the confinement of the Ni in the solid solution. It is proven that the stability of catalyst was improved by the strong metal-support interaction, small metallic particles, and high basicity of the catalyst. This study highlighted the contribution of MSN and in-situ electrolysis method in the catalysis research, particularly in the utilization of CO2 and CH4 for synthesis production
dc.description.sponsorship	Faculty of Chemical Engineering
dc.identifier.uri	http://openscience.utm.my/handle/123456789/1229
dc.language.iso	en
dc.publisher	Universiti Teknologi Malaysia
dc.subject	Methanation
dc.subject	Carbon dioxide—Utilization
dc.subject	Catalysts—Structure-activity relationships
dc.title	Nickel supported on mesostructured silica nanoparticles for carbon dioxide reforming of methane
dc.type	Thesis
dc.type	Dataset

Nickel supported on mesostructured silica nanoparticles for carbon dioxide reforming of methane

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