This paper presents our recent effort on application of nanoimprint technology into passive MEMS-based direct methanol fuel cell (DMFC) for chip-scale power-embedded system. We fabricated and characterized five kinds of micro DMFC with different nanoimprint pattern and catalyst layers. It was found that the measured fuel cell performance varied with the nanoimprinted patterns because they affec...

The performance of a direct methanol alkaline anion-exchange membrane (Fumatech FAA3) fuel cell with Pt-free nitrogen-doped few-walled carbon nanotubes (N-FWCNT) as the cathode catalyst is compared with a commercial supported Pt catalyst. The ionomer content of the N-FWCNT cathode catalyst layer is therefore optimized and it is shown to be 40 wt% of FAA3. Scanning electron microscopy images of ...

Vertical single-walled and double-walled carbon nanotube (SWNT and DWNT) arrays have been grown using a catalyst embedded within the pore walls of a porous anodic alumina (PAA) template. The initial film structure consisted of a SiOx adhesion layer, a Ti layer, a bottom Al layer, a Fe layer, and a top Al layer deposited on a Si wafer. The Al and Fe layers were subsequently anodized to create a ...

In polymer electrolyte membrane fuel cells (PEMFCs), because the reaction rate in the cathode is slower than that in the anode, the cathode catalyst layers require more catalyst loading than the anodes [1]. Much research has been focused on improving the catalytic activity in cathodes and simultaneously reducing the amount of Pt supported by carbon black, which is the most commonly used cathode...

The performance of polymer electrolyte membrane (PEM) fuel cell is mainly influenced by ohmic, activation, and concentration overpotentials. Ohmic overpotential is directly proportional to electric resistance in the fuel cell components that can be estimated from the experimental data or from the empirical relation for the cell polarization curve. However, such simple relation is not available ...

Fe₃O₄ microsphere is a good candidate as support for catalyst because of its unique magnetic property and large surface area. Coating Fe₃O₄ microspheres with other materials can protect them from being dissolved in acid solution or add functional groups on their surface to adsorb catalyst. In this paper, a carbon layer was coated onto Fe₃O₄ microspheres by hydrothermal treatment using polyethyl...

A novel catalyst layer structure is proposed for our miniature fuel cells. In our fuel cells, conventionally porous Pt was used as a catalyst layer. In order to reduce the Pt amount, instead of porous Pt, porous Pd was formed on a Si chip and Pt was deposited atomically on the Pd by UPD-SLRR(Under Potential Deposition – Surface Limited Redox Replacement). The PdPt catalyst showed satisfying per...

In this study, a solid acid was prepared by the sulfonation of surface modified α-zirconium phosphate (ZrP) single-layer nanosheets (SO3H@ZrP), and the prepared solid acid was investigated for the esterification of oleic acid with methanol to produce biodiesel. For comparison, liquid H2SO4 and commercial Amberlyst® 15 catalyst were also evaluated for the same reaction under the same conditions....

The growth of vertically aligned carbon nanotubes using a direct current plasma enhanced chemical vapor deposition system is reported. The growth properties are studied as a function of the Ni catalyst layer thickness, bias voltage, deposition temperature, C2H2:NH3 ratio, and pressure. It was found that the diameter, growth rate, and areal density of the nanotubes are controlled by the initial ...