Sinteza CeO2 dopiranog sa Zr metodom sagorijevanja

master's thesis

• Title (english): Combustion synthesis of Zr-doped CeO2
• Author: Helena Bach-Rojecky
• Mentor: Stanislav Kurajica (mentor)
• Committee member: Stanislav Kurajica (predsjednik povjerenstva)
• Committee member: Juraj Šipušić (član povjerenstva)
• Committee member: Marina Duplančić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2022-09-07, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Cerijev (IV) oksid dopiran cirkonijem obećavajući je katalitički materijal opsežno istražen i korišten u katalitičkim konverterima s trostrukim djelovanjem, oksidaciji hlapivih organskih spojeva (VOCs), gorivnim člancima s čvrstim oksidom kao elektrolitom itd. Ovako širok interes ovaj materijal zahvaljuje svom visokom kapacitetu skladištenja i otpuštanja kisika, dobrim redukcijskim svojstvima i toplinskoj stabilnosti. U ovom radu su čiste i cirkonijem dopirane nanočestice (Ce1-xZrxO2, gdje je x = 0, 0,1, 0,2 i 0,3) pripremljene metodom sagorijevanja koristeći glicin kao gorivo te cerijeve i cirkonijeve nitrate kao oksidanse. Dobiveni prašci karakterizirani su rendgenskom difrakcijskom analizom (XRD), infracrvenom spektroskopijom s Fourierovom transformacijom (FTIR), diferencijalnom toplinskom i termogravimetrijskom analizom (DTA-TGA) te pretražnom elektronskom mikroskopijom (SEM). Katalitička aktivnost pripremljenih nanokatalizatora ispitana je u procesu oksidacije VOC. Temperatura sagorijevanja se povećavala s povećanjem udjela cirkonija u uzorcima. Na difraktogramima svih uzoraka uočljivi samo difrakcijski pikovi za cerijev oksid. Veličine kristalita kreću se u rasponu 25,2 do 11,7 nm i ne mijenjaju se značajno nakon toplinske obrade na 500 °C u trajanju od 2 sata, što ukazuje na dobru toplinsku stabilnost pripremljenih uzoraka. SEM analiza je pokazala da su dobiveni uzorci vrlo porozni. Uzorak cerijevog oksida s 10 mol. % Zr pokazao je najbolju katalitičku aktivnost u procesu oksidacije VOC.

Abstract (english)

Zirconium doped ceria is a promising catalytic material extensively researched and used in three way catalytic converters, oxidation of volatile organic compounds (VOCs), solid oxide fuel cells etc. Such wide interest this material owns to its high oxygen storage and release capacity, high reduction properties and thermal stability. In this work, pure and zirconium doped ceria nanoparticles (Ce1-xZrxO2, where x = 0, 0,1, 0,2 and 0,3) were prepared by combustion synthesis using glyceneas fuel and cerium and zirconium nitrates as oxidants. The obtained powders were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential thermal and thermogravimetric analysis (DTA-TGA), as well as scanning electron microscope (SEM). The catalytic activity of the prepared nanocatalysts was tested in the VOCs oxidation process. The combustion temperature increased with the increase of zirconium content in the samples. XRD patterns show solely ceria diffraction peaks. The crystallite sizes are in range from 25,2 to 11,7 nm, and they do not change significantly after thermal treatment at 500 °C for 2 hours, indicating good thermal stability of the prepared samples. SEM analysis showed that the obtained samples are very porous. The ceria sample with 10 mol. % of zirconium exhibited the best catalytic activity in the VOCs oxidation process.

• Keywords: cerijev(IV) oksid; cirkonij; sinteza sagorijevanjem; kataliza
• Keywords (english): ceria; zirconium; combustion synthesis; catalysts
• Language: croatian
• URN:NBN: urn:nbn:hr:149:176790
• Project: Number: IP-2018-01-2963; Title: Hidrotermalna sinteza dopiranog cerij oksidnog nanokatalizatora; Acronym: HOuDiNI; Leader: Stanislav Kurajica; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra primijenjene kemije (magistar/magistra primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-03-10 15:19:35