Membrane na osnovi grafena za uporabo v etanolnih gorivnih celicah

Kozamernik, Mark (author), Genorio, Boštjan (mentor)

Grafen je stabilen 2-D material z izjemnimi lastnostmi, kot so dobra mehanska obstojnost, visoka električna in termična prevodnost. Potencialno se ga lahko uporablja v katalitskih procesih, polimernih nanokompozitih in elektrokemijskih napravah, kot so: superkondenzatorji, baterije, sončne in gorivne celice. Pričakuje se, da bodo gorivne celice postale tehnologija prihodnosti, predvsem za pretvorbo energije. Med raznimi vrstami gorivnih celic se etanolnim gorivnim celicam posveča veliko pozornosti zaradi enostavne dostopnosti etanola, varnega skladiščenja in uporabe relativno poceni ter neplemenitih kovinskih katalizatorjev. Ključni sestavni del gorivnih celic predstavlja ionska izmenjevalna membrana, ki zagotavlja ionsko prevodnost ter deluje kot separator med anodo in katodo. Komercializacija etanolnih gorivnih celic je trenutno še vedno omejena zaradi počasne kinetike anodnih elektrokemijskih reakcij in prehajanja etanola skozi membrano. V ta namen je potrebno razviti nove membrane z izboljšanimi lastnostmi. V okviru magistrskega dela sem preko kemijskih postopkov iz večstenskih ogljikovih nanocevk (MWCNT) uspešno pripravil derivate grafena. S pomočjo karakterizacijskih metod, kot so vrstična elektronska mikroskopija (SEM), elementni analizi (CHN in EDS) ter analiza specifične površine (BET), sem analiziral lastnosti dobljenih materialov. Z uvajanjem grafena dopiranega z dušikom (N-grafen) v hitozan so bile izdelane kompozitne membrane z izboljšanimi lastnostmi. Z namenom merjenja električne upornosti membran sem razvil in testiral ustrezno elektrokemijsko celico. Ionsko prevodnost membran sem določil z metodo elektrokemijske impedančne spektroskopije (EIS). Ugotovil sem, da so največji potencial izkazale membrane z 0,04 ut. % N-grafena, saj so dosegle najvišje vrednosti ionske prevodnosti.

• Language: Slovenian
• Keywords: grafen, etanol, gorivne celice, membrana, ionska prevodnost
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2021
• PID: 20.500.12556/RUL-130627
• COBISS.SI-ID: 85481731
• Publication date in RUL: 16.09.2021

KOZAMERNIK, Mark, 2021, Membrane na osnovi grafena za uporabo v etanolnih gorivnih celicah [online]. Master’s thesis. [Accessed 25 March 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=130627

Secondary language

• Language: English
• Title: Graphene based membranes for direct ethanol fuel cell applications

Abstract

Graphene is a stable two-dimensional material with outstanding properties, such as good mechanical strength, high electrical and thermal conductivity. It can be potentially used in catalytic processes, polymer nanocomposites and electrochemical devices, such as: supercapacitors, batteries, solar and fuel cells. Fuel cells are expected to become the technology of the future, especially for energy conversion. Among the various types of fuel cells, much attention is paid to ethanol fuel cells due to easy availability of ethanol, safe storage and the use of relatively inexpensive and non-noble metal catalysts. A key component of fuel cells is the ion exchange membrane, which provides ionic conductivity and acts as a separator between the anode and cathode. The commercialization of ethanol fuel cells is currently still limited due to the slow kinetics of anodic electrochemical reactions and the crossover of ethanol across the membrane. To this end, new membranes with improved properties need to be developed. As part of my master's thesis I used chemical procedures to produce graphene derivatives from multiwalled carbon nanotubes (MWCNT). By using characterization methods, such as scanning electron microscopy (SEM), elemental analysis (CHN and EDS) and BET-specific surface analysis, I analyzed the properties of the obtained materials. By introducing nitrogen doped graphene (N-graphene) into chitosan, composite membranes with improved properties were fabricated. To measure the electrical resistance of the membranes, I developed and tested a suitable electrochemical cell. The ionic conductivity of the membranes was determined by electrochemical impedance spectroscopy (EIS). The most promising results were shown by membranes with 0,04 wt. % N-graphene, as they achieved the highest values of ionic conductivity.

• Keywords: graphene, ethanol, fuel cells, membrane, ionic conductivity