Low Humidifying Proton Exchange Membrane Fuel Cells with Enhanced Power and Pt–C–h-SiO₂ Anodes Prepared by Electrophoretic Deposition

Abstract

Hydrophilic anodes were prepared by electrophoretic deposition using a slurry containing hollow SiO2 (h-SiO2) nanospheres and commercial Pt–C nanocatalysts. Low humidifying membrane–electrolyte assemblies (MEAs) were then prepared, which were incorporated into single proton exchange membrane fuel cells (PEMFCs). The effect of humidity on the cell voltage and that of the h-SiO2 mass fraction on the MEA power performance and resistance were examined. The MEA stability was evaluated. Adding h-SiO2 nanospheres to the catalyst increased the Pt mass activity from 1997 to 2657 A/gPt at an operating voltage of 0.6 V at a 100% relative humidity (RH); it increased from 1557 to 2611 A/gPt at 0.6 V and 30% RH. The current density voltage (i–V) and electrochemical-impedance results showed that the addition of h-SiO2 reduced both anode activation loss and ohmic polarization. In addition, the low humidifying MEAs exhibited the same i–V relationship over a wide humidity range. After long-term operation in the absence of moisture, the cell voltage of a standard MEA was found to reduce by 15.55% whereas that of our proposed single cell dropped by only 7.18%. The power density of our proposed MEA was enhanced by a factor of 1.5 relative to a regular MEA.

Hollow TiO2 Microsphere/Graphene Composite Photocatalyst for CO2 Photoreduction

“…Scientists and engineers have been developing diverse green technologies, ranging from CO 2 capture to renewable energy and energy conversion devices, to combat the ever-increasing impact of the greenhouse effect and energy crisis on the environment [1][2][3][4][5][6][7][8]. CO 2 photoreduction (CO 2 PR) is the only technology that can consume CO 2 to produce valuable fuels using solar energy.…”

Potential Bifunctional Filler (CeO2–ACNTs) for Nafion Matrix toward Extended Electrochemical Power Density and Durability in Proton-Exchange Membrane Fuel Cells Operating at Reduced Relative Humidity

“…Proton-exchange membrane fuel cells (PEMFCs) are of great interest to both academic and industrial researchers because of their high conversion efficiency, high power density, nonpolluting exhausts, and quiet operation. , However, one of the major challenges is development of PEMFCs capable of operating at low relative humidity (RH) because PEMFCs consume 20% of generated power with a supporting external humidifier. − One promising approach to alleviate this challenge is to exploit a proton-exchange membrane (PEM) capable of operating under low RH. Because of its superior proton conductivity under wet condition and chemical-mechanical stability, Dupont’s Nafion is considered a state-of-the-art PEM of hydrated PEMFCs. − Unfortunately, proton conductivity of Nafion deeply relies on water contents in PEM, and operation of PEMFCs at low RH is accordingly limited .…”

“…Proton-exchange membrane fuel cells (PEMFCs) are of great interest to both academic and industrial researchers because of their high conversion efficiency, high power density, nonpolluting exhausts, and quiet operation. 1,2 However, one of the major challenges is development of PEMFCs capable of operating at low relative humidity (RH) because PEMFCs consume 20% of generated power with a supporting external humidifier. 3−6 One promising approach to alleviate this challenge is to exploit a proton-exchange membrane (PEM) capable of operating under low RH.…”

Improving the Supercapacitor Performance by Dispersing SiO2 Microspheres in Electrodes

“…24 We observed a similar phenomenon in the proton-exchange membrane fuel cells; the addition of insulating SiO 2 microspheres in the electrode matrix resulted in a 1.5-fold increase in power density and improved electrode durability. 25 Meanwhile, SiO 2 has also been adopted as an electrode component in several supercapacitor studies. 21,22,26−30 However, the advantage of SiO 2 for the electrolyte−electrode affinity was overlooked; these studies attributed the improvement to the spatial and templating effects of SiO 2 .…”