Date of Defense
8-4-2026 11:00 AM
Location
Microsoft Teams
Document Type
Dissertation Defense
Degree Name
Doctor of Philosophy in Chemistry
College
COS
Department
Chemistry
First Advisor
Abbas Khaleel
Keywords
Methane reforming, syngas, partial oxidation, dry reforming, Ni catalysts, coking, methane cracking.
Abstract
Ni-based catalysts are widely used in methane reforming and hydrogen production, but their industrial application is limited by deactivation caused by carbon deposition (coking). This dissertation examines the role of iron as a dopant in improving catalytic performance and coking resistance, with emphasis on its incorporation method and impact on coke oxidation during different methane reforming reactions.
The results show that dispersing iron ions within the γ-Al₂O₃ support significantly enhances catalyst coking resistance and hence catalyst performance under partial oxidation and combined partial oxidation-dry reforming conditions. This improvement is attributed, mainly, to the redox function of Fe and the enhanced Ni reducibility. In contrast, co-impregnation of iron and nickel on the surface facilitates alloy formation, accelerates methane decomposition and enhances carbon formation. Iron loading and catalysts pretreatment strongly influences the catalysts composition and performance.
Furthermore, a sol-gel prepared Ni/FeAl₂O₄ catalyst demonstrated superior hydrogen production in methane cracking compared to conventional Ni catalysts on other support-supported systems, due to a significant role of the support in the adsorption and activation of methane molecules.
This study highlights the critical importance of Ni catalysts’ modification by well-dispersed Fe ions to enhance their coking resistance during methane reforming reactions. The results showed that the impact of Fe as a modifier depends on the method of its incorporation in the catalyst and on its concentration. The study also showed that the composition of the support can play a significant role in the reaction path where the presence of FeAl₂O₄ was found to promote methane cracking to carbon and hydrogen.
Included in
SYNTHESIS AND CATALYTIC ACTIVITY TESTING OF COKE-RESISTANT NICKEL-BASED CATALYSTS FOR METHANE REFORMING AND HYDROGEN PRODUCTION
Microsoft Teams
Ni-based catalysts are widely used in methane reforming and hydrogen production, but their industrial application is limited by deactivation caused by carbon deposition (coking). This dissertation examines the role of iron as a dopant in improving catalytic performance and coking resistance, with emphasis on its incorporation method and impact on coke oxidation during different methane reforming reactions.
The results show that dispersing iron ions within the γ-Al₂O₃ support significantly enhances catalyst coking resistance and hence catalyst performance under partial oxidation and combined partial oxidation-dry reforming conditions. This improvement is attributed, mainly, to the redox function of Fe and the enhanced Ni reducibility. In contrast, co-impregnation of iron and nickel on the surface facilitates alloy formation, accelerates methane decomposition and enhances carbon formation. Iron loading and catalysts pretreatment strongly influences the catalysts composition and performance.
Furthermore, a sol-gel prepared Ni/FeAl₂O₄ catalyst demonstrated superior hydrogen production in methane cracking compared to conventional Ni catalysts on other support-supported systems, due to a significant role of the support in the adsorption and activation of methane molecules.
This study highlights the critical importance of Ni catalysts’ modification by well-dispersed Fe ions to enhance their coking resistance during methane reforming reactions. The results showed that the impact of Fe as a modifier depends on the method of its incorporation in the catalyst and on its concentration. The study also showed that the composition of the support can play a significant role in the reaction path where the presence of FeAl₂O₄ was found to promote methane cracking to carbon and hydrogen.