PDF Publication Title:
Text from PDF Page: 016
Energies 2020, 13, 420 16 of 96 the evaporation of the electrolyte [181]. The required voltage slightly increases with pressure increase, but the main advantage is the reduction of energy demand for hydrogen compression. The rate-determining step of the water electrolysis is the adsorption reaction that occurs at the cathode. Catalysts under investigation for both improved activity and stability of the electrodes could be classified in three groups: (i) noble metals such as Pt, Pd, Ir, Ru, Ag and their alloys including binary-alloy based on Pt with Sm, Ho, Ce or alloys with low-cost transition metals or doped with non-metal compounds, (ii) transition metals including Ni, Mn, Cu, Mo, W, Co, Fe and their alloys, and (iii) non-metal elements e.g., C, N, S, O, P and their alloys [182]. The inexpensive nickel-based catalyst is the most studied materials as an alternative to precious and low-abundant platinum-based materials. The Ni-based catalyst offers a good catalytic activity but is affected by long-term instability due to the formation of nickel hydride compounds that induce the overpotential increment [183]. The electrode instability is provoked by the nickel hydride formation that reduces the active surface area of the catalyst materials [184]. Electrocatalytic activity and stability can be improved with the synthesis of electrocatalytic materials such as metals or metal oxides or modifying the nanostructure of the surface area [185]. Ni-Mo alloy electrocatalyst is widely explored because of their high corrosion resistance, low hydrogen overvoltage, long-term stability, good hardness and good resistance to wear [186]. Brown et al. [187] explore the electrochemical properties of a variety of nickel-based binary or ternary alloys (Ni, Co, Mo, W, V) on a metallic substrate. Ni-Mo catalyst results in the most active and stable electrode material. Arul Raj [188] explores the electrocatalytic activity of numerous binary-composite, confirming the highest catalytic activity of Ni-Mo alloys and ranking in the following order: Ni-Mo > Ni-Zn > Ni-Co > Ni-W > Ni-Fe > Ni-Cr. Raney-alloys are composed by Ni, Co and F doped with active materials (Al, Zn) that enhance the active surface area and electrocatalytic activity of electrodes [186]. A drawback is the dissolution of active compound that reduces the performance over time. Electrode coating are deposited via vapor plasma spraying [189], electrodeposition [190] or chemical and vapor deposition [170]. The characteristic of the nanostructured morphology of electrocatalyst is an essential parameter for the catalytic activity of electrodes, even if the ohmic voltage arises due to gas bubble formation inside the nanostructure. However, gas bubble resistance could be minimized with optimal cell configuration or operational temperature enhancement [191]. The material nanostructure increases the specific active area available for the catalysis of reactions, encourages chemical reactions since the chemical activity is higher at discontinuities or defects and enhances the charge transfer kinetics due to shorter electron-transfer distances and rapid diffusion rate [192]. Ganci et al. [193] demonstrate that the surface area of a Ni-based catalyst electrodeposited inside the pores of a polycarbonate membrane increases of approximately two orders of magnitude with a favorable effect on electrocatalytic activity. Finally, catalyst-based heterostructures are realized, forming a heterojunction between two catalytic compounds (e.g., Ni and Pt) to realize a more active catalyst tuning the adsorption and desorption energy [183]. Subbaraman et al. [194] first proposed a heterojunction device with Ni(OH)2 nanoparticles on a platinum substrate and demonstrated the increase of 8 times the catalytic activity of the hydrogen evolution reaction. 3.1.2. Polymer Electrolyte Membrane Electrolysis Cells The polymer electrolyte membrane (PEM) electrolyzer was first developed by General Electrics in the 1960s [195] when Grubb [196] applied the ion-exchange membranes as solid electrolytes in batteries. The hydrogen purity is higher than 99.99% without post-treatment [154]. The low operating temperatures (50–80 ◦C), the rapid cold start up (from seconds to minutes) and the wide operating range (5%–100% of the nominal load) make the dynamic operation possible [195,197]. The main PEM components are the membrane electrode assembly (MEA), the gas diffusion layer, the interconnector plate, and a carbon gasket that seals the cell (see Figure 7). The membrane electrode assembly consists of a perfluorosulfonic acid polymer membrane (Nafion®, Fumapem®, Aciplex®, Flemion®), an ionomer solution and the electrocatalyst at anode and cathode [198].PDF Image | Green Synthetic Fuels
PDF Search Title:
Green Synthetic FuelsOriginal File Name Searched:
energies-13-00420.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |