Abstract An advanced cathode design can improve the power performance and durability of proton exchange membrane fuel cells (PEMFCs), thus reducing stack cost cell vehicles (FCVs). Recent studies on highly active Pt alloy catalysts, short-side-chain polyfluorinated sulfonic acid (PFSA) ionomer 3D-ordered electrodes have imparted PEMFCs with boosted density. To achieve compacted target 6 kW/L or...

Oxygen reduction reaction (ORR) and oxygen evolution (OER) play crucial roles in energy conversion storage devices. Particularly, the bifunctional ORR/OER catalysts are core components rechargeable metal–air batteries, which have shown great promise achieving "carbon emissions peak carbon neutrality" goals. However, sluggish ORR OER kinetics at cathode significantly hinder performance of batter...

The Magnetron is one of the efficiency high-power microwave source, although the energy conversion efficiency decreases with pulsed-power relativistic electron beam. We study the capability to increase energy conversion efficiency of Relativistic Magnetron by using Transparent Cathode. The Transparent-Cathode consists of independent cathode strips. Each cathode strip caused azimuthal magnetic f...

in this research different types of al2o3 were used as supports to prepare catalysts for dehydrogenation of isobutane to isobutene. these supports were al2o3 from merck, axen and gamma al2o3 synthesized from al(oh)3. sn/pt/al2o3 catalysts were prepared by sequential impregnation, at first pt and then sn was deposited. characterization of catalysts was performed by x-ray powder diffraction (xrd)...

The purpose of this study was to polish electrolytically a large maxillary denture base-shaped titanium specimen with non-aqueous electrolyte. The test specimen was prepared by bending a sheet of titanium plate. An additional cathode was made by cutting off part of a cylindrical cathode. The effects of the shape and position of the additional cathode were investigated. Selected factors of the a...

A rectangular gridded ion thruster discharge chamber is investigated for operation with multiple discharge cathode assemblies. The multiple-cathode approach attempts to increase thruster throughput and lifetime by operating three discharge cathode assemblies sequentially, possibly providing a threefold increase in discharge chamber life. Previous multiple-cathode electric propulsion devices, su...

Direct methanol fuel cells (DMFCs) are promising electrochemical systems capable of producing electricity from the oxidation and reduction oxygen. In this work, effectiveness addition sulfuric acid as a supporting electrolyte for composition was assessed. The results showed that peak power curve in DMFCs with Pt/C cathode electrocatalysts increased progressively 70 mW cm−2 (0 mM H2SO4) to 115 c...

Advances in the development of precious-group metal-free (PGM-free) catalysts for oxygen reduction reaction (ORR) fuel cell cathodes have produced active that reduce performance gap to incumbent Pt-based materials. However, utilization state-of-the-art PGM-free commercial applications is currently impeded by their relatively low durability. Methods designed study catalyst degradation operation ...

Nano-scale palladium was bio-manufactured via enzymatically-mediated deposition of Pd(II) from solution. The bio-accumulated metal palladium crystals were processed and applied onto carbon paper and tested as anodes in a proton exchange membrane (PEM) fuel cell for power production. Up to 85% and 31% of the maximum power generation was achieved by Bio-Pd catalysts made using two strains of bact...