scholarly journals The enhanced activity of Pt–Ce nanoalloy for oxygen electroreduction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juan Qin ◽  
Yafeng Zhang ◽  
Deying Leng ◽  
Feng Yin
Keyword(s):  
Hydrogen Reduction ◽  
Polymer Electrolyte Membrane ◽  
Clean Energy ◽  
Reduction Reaction ◽  
Future Perspectives ◽  
Electrolyte Membrane ◽  
Reduction Techniques ◽  
Orr Activity ◽  
Clean Energy Source ◽  
Alloy Catalysts

Abstract The widespread use of low-temperature polymer electrolyte membrane fuel cells for clean energy source require significant reductions in the amount of expensive electrocatalyst Pt for the oxygen reduction reaction (ORR). Pt based binary alloys are promising materials for more active and stable electrocatalysts. In this paper, we studied Pt–Ce nanoalloy, which was prepared by hydrogen reduction techniques as ORR electrocatalysts. Among all PtCe alloy catalysts, the PtCe/C-800 ℃ shows superior ORR activity, stability and durability compared to commercial Pt/C. The results presented in this paper will provide the future perspectives to research based on Pt-RE (RE = Ce, Dy, Gd, Er, Sm, and La) alloy as an novel electrocatalyst for various electrocatalytic reactions.

scholarly journals Probing Active Sites on Metal-Free, Nitrogen-Doped Carbons for Oxygen Electroreduction: A Review

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 509 ◽  
Author(s):  
Ni Zhou ◽  
Nan Wang ◽  
Zexing Wu ◽  
Ligui Li
Keyword(s):  
Active Sites ◽  
Catalytic Mechanism ◽  
Low Cost ◽  
Polymer Electrolyte Membrane ◽  
Precious Metals ◽  
Reduction Reaction ◽  
Nitrogen Doped ◽  
Metal Free ◽  
Electrolyte Membrane ◽  
Orr Activity

The Metal-free nitrogen-doped carbons represent an emerging low-cost nonprecious electrocatalyst for oxygen reduction reaction (ORR) that is a sluggish process at the cathode of polymer electrolyte membrane fuel cells (PEMFCs) and a verity of metal-air batteries. During the past few years, the ORR catalytic activity of nitrogen-doped carbons has been significantly increased, making them highly competitive alternatives to conventional precious metals based electrocatalysts for ORR. However, controversies remain in the unambiguous identification of the ORR active sites on nitrogen-doped carbons. This review summarizes the recent progress in probing the potential active sites on metal-free nitrogen-doped carbons for ORR, aiming to gain in-depth understanding of the ORR catalytic mechanism on nitrogen-doped carbons for further enhancing ORR activity.

scholarly journals Synthesis and Characterization of Cobalt and Nitrogen Co-Doped Peat-Derived Carbon Catalysts for Oxygen Reduction in Acidic Media

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 715
Author(s):  
Rutha Jäger ◽  
Patrick Teppor ◽  
Maarja Paalo ◽  
Meelis Härmas ◽  
Anu Adamson ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Polymer Electrolyte Membrane ◽  
Rotating Disk ◽  
Platinum Group Metal ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Carbon Supports ◽  
Electrolyte Membrane ◽  
Orr Activity ◽  
Carbon Catalysts

In this study, several peat-derived carbons (PDC) were synthesized using various carbonization protocols. It was found that depending on the carbonization method, carbons with very different surface morphologies, elemental compositions, porosities, and oxygen reduction reaction (ORR) activities were obtained. Five carbons were used as carbon supports to synthesize Co-N/PDC catalysts, and five different ORR catalysts were acquired. The surface analysis revealed that a higher nitrogen content, number of surface oxide defects, and higher specific surface area lead to higher ORR activity of the Co-N/PDC catalysts in acidic solution. The catalyst Co-N/C-2(ZnCl2), which was synthesized from ZnCl2-activated and pyrolyzed peat, showed the highest ORR activity in both rotating disk electrode and polymer electrolyte membrane fuel cell tests. A maximum power density value of 210 mW cm−2 has been obtained. The results of this study indicate that PDCs are promising candidates for the synthesis of active non-platinum group metal type catalysts.

scholarly journals Development of Porous Pt Electrocatalysts for Oxygen Reduction and Evolution Reactions

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2398
Author(s):  
Marika Muto ◽  
Mayumi Nagayama ◽  
Kazunari Sasaki ◽  
Akari Hayashi
Keyword(s):  
Oxygen Reduction ◽  
Current Density ◽  
Polymer Electrolyte Membrane ◽  
Porous Metal ◽  
Pem Fuel Cells ◽  
Reduction Reaction ◽  
Electrolyte Membrane ◽  
Catalyst Layers ◽  
Pt Electrocatalysts ◽  
Pt Black

Porous Pt electrocatalysts have been developed as an example of carbon-free porous metal catalysts in anticipation of polymer electrolyte membrane (PEM) fuel cells and PEM water electrolyzers through the assembly of the metal precursor and surfactant. In this study, porous Pt was structurally evaluated and found to have a porous structure composed of connected Pt particles. The resulting specific electrochemical surface area (ECSA) of porous Pt was 12.4 m2 g−1, which was higher than that of commercially available Pt black. Accordingly, porous Pt showed higher oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity than Pt black. When the activity was compared to that of a common carbon-supported electrocatalyst, Pt/ketjen black (KB), porous Pt showed a comparable ORR current density (2.5 mA cm−2 at 0.9 V for Pt/KB and 2.1 mA cm−2 at 0.9 V for porous Pt), and OER current density (6.8 mA cm−2 at 1.8 V for Pt/KB and 7.0 mA cm−1 at 1.8 V), even though the ECSA of porous Pt was only one-sixth that of Pt/KB. Moreover, it exhibited a higher durability against 1.8 V. In addition, when catalyst layers were spray-printed on the Nafion® membrane, porous Pt displayed more uniform layers in comparison to Pt black, showing an advantage in its usage as a thin layer.

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