Document Details

Document Type : Thesis 
Document Title :
CO2 Hydrogenation to Methanol: Optimizing Pd:Zn Molar Ratio in PdZn/CeO2 Catalyst
هدرجة ثاني أكسيد الكربون لإنتاج الميثانول: تحسين النسبة المولارية للبلاديوم إلى الزنك في محفز:البلاديوم الزنك/ أكسيد السيريوم
 
Subject : Faculty of Engineering 
Document Language : Arabic 
Abstract : Sustainable conversion of CO2 via hydrogenation will not only serve as an alternative route to address global demand for methanol but also mitigate the climate change challenges, with the condition that H2 must be produced from green sources. This thesis reports the optimization of Pd:Zn molar ratio (0.7 to 1.1) over CeO2 support prepared using sol-gel method and tested for CO2 hydrogenation to methanol under mild reaction conditions. The results revealed that catalytic activity increases with the increase Pd:Zn molar ratio up to 1.0 and then showed a decline in activity. Therefore, 1.0PdZn/CeO2 is the optimum catalyst for CO2 hydrogenation to methanol among the investigated catalysts. The best operating condition for 1.0PdZn/CeO2 catalyst is at 220oC, 20bar and 2400h-1 GHSV with stoichiometric feed ratio (CO2/H2 = 1:3), having 14% CO2 conversion and 95% methanol selectivity. Catalyst reduced at high temperature (550oC) under H2 flow formed Ce3+ and PdZn alloy (via Pd2Zn intermediate) creating the active sites for CO2 and atomic H adsorption and generates a strong metal surface interaction which is responsible for the high catalytic activity. Catalysts surface analysis by XPS study for Pdo oxidation state and surface Pd:Zn atomic ratio goes through a maximum for 1.0PdZn/CeO2 which is well correlated with experimental observation for high space time yield of methanol. In-situ DRIFTS study also revealed the surface kinetics of methanol formation proposing two different reaction mechanisms competing over the surface via (1) Formaldehyde (2) Formic acid surface reaction intermediates. 
Supervisor : Dr. Sharif Fakhruz Zaman 
Thesis Type : Master Thesis 
Publishing Year : 1440 AH
2019 AD 
Added Date : Wednesday, August 21, 2019 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
اوبيمي عبد الله اوجيلاديOJELADE, OPEYEMI ABDULAHIResearcherMaster 

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