The efficiency of harvesting the energy in proton exchange membrane fuel cells (PEM-FC), like in all other types of fuel-cells, is mainly limited by the activity of the cathode catalyst for oxygen reducing reaction (ORR). Various catalysts, such as noble metals, intermetallic alloys, carbon-based supports, metal chalcogenides and carbides, are used to reduce the ORR temperature and achieve maxi...

Both Keggin-type phosphotungstic acid (HPW) and Pd are not prominent catalysts towards the oxygen reduction (ORR), but their composite Pd-HPW catalyst produces a significantly higher electrochemical activity for the ORR in acidic media. The novel composite catalyst was synthesized by self-assembly of HPW on multi-walled carbon nanotubes (MWCNTs) via the electrostatic attraction between negative...

Direct methanol fuel cells (DMFCs) are electrochemical devices that efficiently produce electricity and are characterized by a large flexibility for portable applications and high energy density. Methanol crossover is one of the main obstacles for DMFC commercialization, forcing the search for highly electro-active and methanol tolerant cathodes. In the present work, carbon-supported Pd and PdF...

The effect of different cathode strategies (mullite/MnO2, Plexiglas/Gore-Tex/MnO2, mullite/coal fly ash, mullite/biochar, mullite/activated carbon) on the performance air-cathode microbial fuel cells (MFCs) was investigated. highest maximum power output observed using MnO2 catalyst pasted Gore-Tex cloth (7.7 mW/m3), yet coulombic efficiencies (CEs) were achieved (CE 23.5 ± 2.7%) and coal ash 20...

Aqueous Zn–CO 2 battery possesses a large theoretical capacity of 820 mAh g -1 (5855 cm -3 ) and high safety, showing unique position in carbon neutrality and/or reduction energy conversion storage, which has developed rapidly recent years. However, obstacles such as low value-added products, current density, overvoltage, finite cycles impede its practical application. Cathode catalysts, key co...

Here we present an autonomous implantable device for vasopressin monitoring and prevention of latephase hemorrhagic shock powered using a novel non-enzymatic fuel cell unit. The device consists of a biosensor, drug delivery device and fuel cell unit. The innovative stacked single-layer fuel cell (SLFC) design allows to achieve small packaging volume and reduces oxygen cross-over at the anode re...

At present, platinum-based catalysts are the best cathode catalysts, but due to their high prices, they difficult use widely. Under alkaline conditions, silver is a better low-cost substitute. Here, physical preparation method—electrical discharge machining (EDM)—is used prepare Ag0 nanoparticles. The method simple and has yield. diameter of prepared nanoparticles about 30 nm nanoparticle surfa...

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Petri Kanninen Name of the doctoral dissertation Characterization of nanostructured catalysts and silicon microstructures in polymer electrolyte membrane fuel cells Publisher School of Chemical Technology Unit Department of Chemistry Series Aalto University publication series DOCTORAL DISSERTATIONS 76/2014 Field of research Ph...