electro-catalytic oxidation of cellulose at au electrode by ari ivaska
TRANSCRIPT
![Page 1: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/1.jpg)
Electro-catalytic oxidation of cellulose at Au electrode
Ari Ivaska, Yasuhito Sugano, Rose-Marie Latonen, Marceline Akieh and Johan Bobacka
Process Chemistry Centre, Åbo Akademi UniversityBiskopsgatan 8, FI-20500 Turku, Finland
ACES: European Dimension21.5. 2015
ChemSusChem, 2014, 7, 2240-2247
![Page 2: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/2.jpg)
Molecular structure of cellulose
Polysaccharide: β(1→4) linked D-glucose units
Insoluble in pure water but can be dissolved in 1.3 M NaOH
![Page 3: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/3.jpg)
CVs of cellulose at Au electrode in 1.3M NaOH
![Page 4: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/4.jpg)
CVs of cellulose at Au electrode in 1.3M NaOH
![Page 5: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/5.jpg)
CVs of cellulose at Au electrode in 1.3M NaOH
![Page 6: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/6.jpg)
CVs of cellulose at Au electrode in 1.3M NaOH
![Page 7: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/7.jpg)
CVs of cellulose at Au electrode in 1.3M NaOH
![Page 8: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/8.jpg)
Mass change during potential cycling in1.3 M NaOH
Scan rate 10 mV/s
![Page 9: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/9.jpg)
Sample treatment
Electrolysis
Original cellulose sample (solid)
Dialysis
Centrifugation
Water insoluble fraction
Water soluble fraction
Dialysis
Centrifugation
Cellulose solution sample (liquid)
Water insoluble fraction
Water soluble fraction
Dissolution in 1.3 M NaOH
Vacume-freeze-drying
Vacume-freeze-drying
![Page 10: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/10.jpg)
SEM images of cellulose samples
original regenerated water insolubleafter electrolysis
water solubleafter electrolysis
![Page 11: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/11.jpg)
TEM images of water-insoluble cellulose after electrolysis
Au nanoparticles ≈ 4 nm
![Page 12: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/12.jpg)
Proposed mechanism
a: initial state: dissolved cellulose in alkaline solutionb: adsorption of OH- ions to the electrode and cellulose molecule approaching the Au-OH site on the electrode surfacec: oxidation of cellulose at the electroded: simultaneous desorption of the oxidation product from the surface and further oxidation of cellulose at the revealed electrode surfacee: desorption of adsorbed OH- ions from the electrode surface.
![Page 13: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/13.jpg)
Conclusions
Cellulose can be oxidized at Au surface Adsorption of OH- ions at the Au surface is of
importance Two type of material is formed during
electrolysis:
- water soluble: containing caboxyl groups
- water insoluble: containing Au nanoparticles
![Page 14: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/14.jpg)
Electroanalysis in Ireland, Electroanalysis na h’Éireann
NIHE, 10-12.6.1986
![Page 15: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/15.jpg)
Meeting in Dublin 5.5.2014
![Page 16: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/16.jpg)
Previous arrival to Dublin
![Page 17: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/17.jpg)
ICSM-2014, Turku, Finland
![Page 18: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/18.jpg)
Thank you for your attention
![Page 19: Electro-catalytic oxidation of cellulose at Au electrode by Ari Ivaska](https://reader035.vdocuments.mx/reader035/viewer/2022062320/55be8657bb61eb195b8b45f0/html5/thumbnails/19.jpg)
CVs of 1 % cellulose solution in 1.3 M NaOH
Different potential ranges