Mehanokemijska sinteza cerijeva(IV) oksida dopiranog manganom

master's thesis

• Title (english): Mechanochemical synthesis of manganese-doped cerium(IV) oxide
• Author: Tea Grbešić
• Mentor: Stanislav Kurajica (mentor)
• Committee member: Stanislav Kurajica (predsjednik povjerenstva)
• Committee member: Nevenka Vrbos (član povjerenstva)
• Committee member: Krunoslav Žižek (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-07-15, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences

Abstract

Uzorci čistog i dopiranog cerijeva(IV) oksida (CeO2) s 10, 20 i 30% mangana pripravljeni su mehanokemijsokm sintezom i potom ispitivani različitim metodama karakterizacije. Kao prekursori korišteni su cerijev(III) klorid, manganov(II) klorid i natrijev karbonat dok je natrijev klorid korišten kao razrjeđivač koji odvaja čestice produkta te sprječava njihov daljnji rast. Uzorci pripravljeni mehanokemijskom sintezom istraživani su rendgenskom difrakcijom (XRD) te diferencijalnom toplinskom i termogravimetrijskom analizom (DTA/TGA). Nakon sinteze uzorci su termički obrađeni na 500 °C u trajanju 2 sata kako bi se iz produkata sinteze dobio CeO2. Obrađeni uzorci podvrgnuti su rendgenskoj difrakcijskoj analizi (XRD), infracrvenoj spektroskopiji s Fourierovom transformacijom (FTIR) i pretražnoj elektronskoj mikroskopiji (SEM). Katalitička aktivnost dobivenih uzoraka ispitana je na procesu oksidacije toluena u integriranom reaktoru s nepokretnim slojem katalizatora, a za detekciju toluena nakon oksidacije korištena je plinska kromatografija (GC).Rezultati su pokazali da mehanokemijskom sintezom, u sintezama s manganom, iz korištenih prekursora uz cerijev(IV) oksid nastaje i birnesit kao sekundarna kristalna faza. Dopiranje manganom dovodi do smanjenja veličine kristalita CeO2, ali ne dovodi do značajnih promjena u morfologiji kao ni katalitičkoj aktivnosti CeO2.

Abstract (english)

Pure ceria samples as well as 10, 20 and 30% manganese doped CeO2 were prepared via mechanochemical synthesis. The as-prepared samples were characterized using X-ray diffraction (XRD) and differential thermal and thermo-gravimetric analysis (DTA-TGA). After mechanochemical synthesis, samples were thermally treated at 500 °C for 2 h, to enable the transformation of synthesis products to CeO2. The thermally treated samples were characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Catalytic activity was tested on toluene oxidation process in an integral up-flow fixed bed reactor and for the detection of residual toluene after oxidation, gas chromatography (GC) was used. During mechanochemical synthesis of doped samples with the used precursors the formation of ceria occurs, along with birnessite as a secondary crystal phase. Doping with manganese caused a decrease in crystallite size. However, no significant differences in morphology or catalytic activity of CeO2 were observed.

• Keywords: cerijev(IV) oksid; mangan; dopiranje; mehanokemijska sinteza; katalitička aktivnost
• Keywords (english): ceria; manganese; doping; mechanochemical synthesis; catalytic activity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:234543
• 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: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-04-07 09:41:18