magistrsko delo
Urška Bukovšek (Author), Sašo Gyergyek (Mentor), Blaž Likozar (Co-mentor)

Abstract

Magistrsko delo predstavlja sintezo magnetno-izločljivih katalizatorjev na osnovi rutenija na ogljikovem nosilcu. Namen magistrskega dela je bil sintetizirati učinkovit katalizator, ki je primerljiv s komercialnim, njegova bistvena prednost pa je ta, da je magneten in ga je možno enostavno separirati z uporabo gradienta zunanjega magnetnega polja. Tekom dela smo sistematično preučevali vpliv postopka priprave na lastnosti Ru/C katalizatorjev. Ogljikove nosilce smo pripravili s hidrotermalno karbonizacijo glukoze v prisotnosti sintetiziranih magnetnih nanodelcev. Delce smo nato žgali v cevni peči, v inertni argonovi atmosferi in jim z mletjem povečali specifično površino. Nadalje smo na njihovo površino sintetizirali Ru nanodelce z redukcijo Ru(acac)3. Izbrane sintetizirane katalizatorje smo testirali za reakcijo hidrogeniranja in deoksigenacije evgenola. Ugotovili smo, da imajo delci, prekriti z ogljikom, žgani pri 750 °C bistveno manj strukturnih defektov grafita, kot pri temperaturi 500 °C, katalizator pa je bolj primerljiv s komercialnim. Nadalje smo ugotovili, da z daljšim časom sinteze v avtoklavu, Ru nanodelci rastejo na površini C nosilca. Prav tako je na površini C nosilca prišlo do nastanka Ru skupkov. Najbolj presenetljiva ugotovitev pa je bila ta, da ima dodatek PVP zelo velik vpliv na celotno sintezo Ru/C katalizatorjev ter na njihovo učinkovitost. PVP je onemogočal vezavo večjih koncentracij Ru(acac)3 na površino C nosilca, brez njegove prisotnosti pa smo lahko koncentracijo Ru(acac)3 kar 5x povečali. Zmanjšal je tudi končno učinkovitost katalizatorjev, Ru nanodelci pa so na površini C nosilca po katalizah močno zrasli. Katalizatorji brez PVP so bili zelo učinkoviti. Najbolj učinkovit je bil katalizator z delci, žganimi pri 500 °C. Bil je tudi bolj učinkovit od katalizatorja z delci, žganimi pri 750 °C ter od komercialnega.

Keywords

magnetno-izločljivi katalizatorji;Ru katalizatorji;C nosilec;hidrogeniranje;deoksigenacija;magistrske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [U. Bukovšek]
UDC: 542.973:66.094.25(043.2)
COBISS: 21028374 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Synthesis of magnetically-separable catalysts based on Ru on carbon
Secondary abstract: The master's thesis presents the synthesis of magnetically-separable catalysts, based on ruthenium on carbon support. The purpose of this master’s thesis was to synthesise an effective catalyst, comparable with commercial, with its main advantage that it’s magnetic and can be easily separated using the gradient of external magnetic field. During the work we systematically studied the influence of the preparation conditions on the properties of the Ru/C catalysts. The carbon support was prepared by hydrothermal carbonization of glucose in the presence of the synthesized magnetic nanoparticles. Then, nanopartilces were pyrolysed in a tube furnace in an argon inert atmosphere. We increase the specific surface of nanoparticles by milling. Further, on their surface Ru nanoparticles with Ru(acac)3 reduction were synthesized. Selected synthesized catalysts were tested for the reaction of hydrogenation and deoxygenation of eugenol. In our work we have determined, that carbon coated nanoparticles, pyrolysed at 750 °C is graphitic with less structural defects than at 500 °C and the catalyst is more comparable with commercial. We also found that with a longer time of synthesis in autoclave, Ru nanoparticles grow on the surface of C support. Also, on the surface of C support the Ru clusters were formed. The most surprising finding was that the PVP addition has very strong influence on the entire synthesis of Ru/C catalysts and their effectiveness. PVP inhibited the binding of higher concentrations of Ru(acac)3 on the surface of C support and without its presence, the concentration of Ru(acac)3 could be increased 5x. PVP also reduced the final efficiency of the catalysts and after the catalysis, Ru nanoparticles grew significantly on C support surface. Catalysts without PVP were very effective. The most efficient catalyst had nanoparticles, pyroliysed at 500 °C. It was also more effective that the catalyst with nanoparticles, pyrolysed at 750 °C and the commercial catalyst.
Secondary keywords: magnetically-separable catalysts;Ru catalysts;C support;hydrogenation;deoxigenation;
URN: URN:SI:UM:
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: XII, 55 str.
ID: 10863503