Kibena-Põldsepp, Elo
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Kibena-Põldsepp, Elo
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Kibena-Põldsepp, Elo
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Item type:Publication, Polymer-derived Co/Ni–SiOC(N) ceramic electrocatalysts for oxygen reduction reaction in fuel cells(Royal Society of Chemistry, 2019-01-15); ; ; ; Cobalt/nickel-containing SiOC-based porous ceramic electrocatalysts were prepared by pyrolysis of poly(methyl silsesquioxane) and poly(methyl phenyl silsesquioxane) as preceramic precursors combined with graphite and Co/Ni metal salts at 1000 °C in an atmosphere of nitrogen. Subsequently, the Co/Ni–SiOC materials were N-doped using dicyandiamide (DCDA) as a nitrogen source and pyrolysed at 800 °C in an inert atmosphere. The structural properties and composition of the catalysts were characterised by scanning electron microscopy (SEM), X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and N2 adsorption analysis. The evaluation of the polymer-derived SiOC(N) ceramic electrocatalysts as a new class of catalysts for the oxygen reaction reduction (ORR) was carried out by the rotating disk electrode (RDE) method under acidic, neutral and alkaline conditions. The O2 reduction studies revealed that the N-doped materials exhibited enhanced ORR performance, confirming the positive influence of the nitrogen functionalities introduced into the catalysts. The Co-containing N-doped SiOC catalyst exhibited significantly higher ORR activity compared with the studied materials along with the highest electron transfer number in all the studied solutions. Long-term ORR performance testing indicated that the durability of this catalyst was superior as compared to that of commercial Pt/C. These observations suggest that the Co-containing N-doped SiOC catalyst is a promising cathode material for fuel cells (FCs) and microbial FC devices.journal articleBand:9173 126 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Ultrafiltration membrane bio‐fuel cell as an energy‐efficient advanced wastewater treatment system(Wiley, 2022-06-11); ; ; ; A novel anaerobic ultrafiltration membrane bio-fuel cell (UFBFC) was concep- tualized to improve the efficiency of wastewater treatment with a reduced foot- print and bioenergy recovery. The system with a working volume of 40 L reached a maximum power density of 23.3 mW/m2 while treating synthetic wastewater with initial chemical oxygen demand (COD) of 2026 ± 61 mg/L and 19.1 mW/m2 while treating actual fish processing wastewater with initial COD of 1915 ± 63 mg/L. The average COD removal efficiency of UFBFC was found to be almost similar (>97%) for both types of wastewaters showing the efficacy of the system in real-life applications comparable to the existing treat- ment systems. The cost-effective longitudinal vibrational mechanism (0.25 $/kLD of treated wastewater), with a frequency of 0.5 Hz and an amplitude of 8 mm, revealed superior anti-biofouling ability for ultrafiltration membrane placed inside the anodic chamber of UFBFC than cost-intensive conventional techniques (117 $/kLD in conventional MBR with aeration). The capacitor- based power management circuit improved the maximum normalized energy recovery (58 Wh/m3) of UFBFC by over twice compared to UFBFC when oper- ated with external resistance of 100 Ω (24 Wh/m3). The harvested energy by UFBFC with capacitor-based power management system thus could success- fully compensate the operational power requirement of the system, proving its practical field-scale applications as an energy-economic advanced wastewater treatment system.journal article179 206