PDF Publication Title:
Text from PDF Page: 002
Nanomaterials 2021, 11, 1017 2 of 12 Anode reaction: CO(NH2)2 + 6 OH− → N2 + CO2 + 5H2O + 6e− E0 = −0.746 V Overall reaction: 2CO(NH2)2 + 3O2 → 2N2 + 2CO2 + 4H2O E0 = +1.146 V Multi-walled carbon nanotubes (MWCNTs) have been used as one-dimensional mate- rials for enhancing the electron conductivity and increasing the surface area of composites for use as cathodes in DUFCs. In addition, MWCNTs are prospectively useful for increasing the porosity of catalysts. MWCNT-supported materials are widely utilized in many types of fuel cells owing to their large surface area and chemical and thermal stability in both basic and acidic media. For practical use in fuel cell catalysts, further physical and chemical treatments are needed to introduce many active sites onto the surface of MWCNTs [6,7]. Chemical activation methods include both covalent and non-covalent functionalization. Generally, non-covalent polymers can modify the delocalized π-electrons of MWCNTs when combined with a conjugated composite via van der Waals forces, π–π interactions, hydrogen bonds, and electrostatic forces. The treatment endows the active surface area of MWNCTs with functional groups such as –COOH, C-OH, and C=O– groups. Acid- activation of functionalized MWCNTs (f-MWCNTs) was implemented using concentrated nitric acid at elevated temperatures to modify the surface of carbon nanotubes in order to produce homogeneous compounds of metal or metal oxides and supported MWCNTs [8]. Compared to noble metals, transition metal oxides (TMOs), as non-platinum catalysts, have superior electrocatalytic performance for oxygen reduction reactions on cathodes of DUFCs, with many advantages such as low cost, durability, anti-poisoning ability, and stability [9]. TMO nanoparticles and MWCNTs were modified with suitable functional groups, combined with linking agents, via covalent bonding, van der Waals forces, π–π stacking interactions, hydrophobic interactions, hydrogen bonding, and electrostatic forces. Transition metals are suitable as catalysts because the cations can adopt variable oxidation states, and their oxides can be combined with other materials to achieve high tolerance and superior ORR performance [10]. However, the use of MWCNTs as catalysts for fuel cell applications is hindered by certain disadvantages, such as metal particle agglomeration, de-adhesion of the catalyst particles from the support materials, carbon degradation, and carbon corrosion [6,11]. Single-metal oxides supported by MWCNTs have been widely investigated as highly efficient bifunctional catalysts. In particular, oxides of transition metals such as Mn, Co, Ni, La, Fe, and Ce have been shown to be highly active toward the ORR [9,12–14]. Co3O4 nanoparticles having Co2+ and Co3+ valence states which occupy their tetrahedral and octahedral sites, respectively, are favorable for oxygen reduction reaction corresponding to changing valence states. That is conducive to the adsorption of O2. Therefore, Co3O4 nanoparticles, as a transition metal oxide, were combined with MWCNTs to achieve enhanced electrochemical performance as the cathode catalyst for the ORR in DUFCs and to reduce the usage of noble metals such as Pt, Pd, and Ru. The combined carbon-based cobalt oxide composites and the construction of homogeneous nano-architectures can considerably enhance the catalyst activity by producing a large catalytically active surface area and affording high conductivity, as well as affording the potential for surface modification [15,16]. Of all the tested metal materials, platinum-based catalysts exhibit the best perfor- mance in the oxygen electro-reduction reaction. However, Pt-based catalysts have not been widely used in fuel cell applications because of their high cost and scarcity. Be- cause of this, other cost-effective non-platinum catalysts have been intensively studied to optimize the efficiency of targeted fuel cells. Mikolajczuk-Zychora et al. employed Pd nanoparticles on MWCNTs as a cathode catalyst for direct formic fuel cells [17]. The results demonstrated that the combination of Pd nanoparticles with carbon-supported materials afforded high electrocatalytic performance toward the ORR. Numerous efforts have been made to improve the catalytic performance and durability of Pd catalysts [9,10,18,19]. Carrión-Satorre et al. investigated the performance of carbon-supported palladium and palladium-ruthenium catalysts in alkaline direct ethanol fuel cells [4,20]. Pd exhibited relatively low electrochemical performance, where the electrochemical activity of Pd couldPDF Image | Effect of Co3O4 Nanoparticles on Improving Catalytic Behavior
PDF Search Title:
Effect of Co3O4 Nanoparticles on Improving Catalytic BehaviorOriginal File Name Searched:
nanomaterials-11-01017.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 |