scholarly journals Oxidatively induced exposure of active surface area during microwave assisted formation of Pt3Co nanoparticles for oxygen reduction reaction

RSC Advances ◽  
2019 ◽  
Vol 9 (31) ◽  
pp. 17979-17987
Author(s):  
Robin Sandström ◽  
Joakim Ekspong ◽  
Eduardo Gracia-Espino ◽  
Thomas Wågberg
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Surface Area ◽  
Microwave Synthesis ◽  
Active Surface ◽  
Reduction Reaction ◽  
Active Surface Area ◽  
Microwave Assisted ◽  
Electrochemically Active ◽  
Electrochemically Active Surface

The oxygen reduction reaction (ORR) is efficiently facilitated platinum catalysts alloyed with Co and reveal high electrochemically active surface area via rapid microwave synthesis.

scholarly journals An Electrocatalytic Activity of AuCeO2/Carbon Catalyst in Fuel Cell Reactions: Oxidation of Borohydride and Reduction of Oxygen

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 342
Author(s):  
Raminta Stagniūnaitė ◽  
Virginija Kepenienė ◽  
Aldona Balčiūnaitė ◽  
Audrius Drabavičius ◽  
Vidas Pakštas ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Surface Area ◽  
Sodium Borohydride ◽  
Electrocatalytic Activity ◽  
Active Surface ◽  
Reduction Reaction ◽  
Active Surface Area ◽  
Onset Potential ◽  
Electrochemically Active ◽  
Electrochemically Active Surface

This paper describes the investigation of electrocatalytic activity of the AuCeO2/C catalyst, prepared using the microwave irradiation method, towards the oxidation of sodium borohydride and oxygen reduction reactions in an alkaline medium. It was found that the obtained AuCeO2/C catalyst with Au loading and electrochemically active surface area of Au nanoparticles (AuNPs) equal to 71 µg cm−2 and 0.05 cm2, respectively, showed an enhanced electrocatalytic activity towards investigated reactions, compared with the Au/C catalyst with an Au loading and electrochemically active surface area of AuNPs equal to 78 µg cm−2 and 0.19 cm2, respectively. The AuCeO2/C catalyst demonstrated ca. 4.5 times higher current density values for the oxidation of sodium borohydride compared with those of the bare Au/C catalyst. Moreover, the onset potential of the oxygen reduction reaction (0.96 V) on the AuCeO2/C catalyst was similar to the commercial Pt/C (0.98 V).

Facile deposition of Pt nanoparticles on Sb-doped SnO2 support with outstanding active surface area for the oxygen reduction reaction

2018 ◽  
Vol 8 (10) ◽  
pp. 2672-2685 ◽  
Author(s):  
Rhiyaad Mohamed ◽  
Tobias Binninger ◽  
Patricia J. Kooyman ◽  
Armin Hoell ◽  
Emiliana Fabbri ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Surface Area ◽  
Pt Nanoparticles ◽  
Active Surface ◽  
Reduction Reaction ◽  
Active Surface Area

Synthesis of Sb–SnO2 supported Pt nanoparticles with an outstanding ECSA for the oxygen reduction reaction.

scholarly journals Oxygen Reduction Reaction (ORR) on a Mixed Titanium and Tantalum Oxy-nitride Catalyst Prepared by the Urea-based Sol-gel Method

2014 ◽  
Vol 17 (2) ◽  
pp. 055-065 ◽  
Author(s):  
A. Seifitokaldani ◽  
M. Perrier ◽  
O. Savadogo
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Surface Area ◽  
Sol Gel ◽  
Active Surface ◽  
Reduction Reaction ◽  
Active Surface Area ◽  
Gel Method ◽  
Sol Gel Method ◽  
Onset Potential

The electrochemical stability and activity of different compositions of titanium and tantalum oxy-nitride nano-catalysts were investigated for the oxygen reduction reaction (ORR). A new sol-gel method was used to produce a nano-powder mixture of Ti and Ta oxynitride from their alkoxides using urea as a nitrogen source. The precursors prepared by the sol-gel method were annealed in a N2 + 3% H2 atmosphere at determined temperatures (500, 700 and 900 °C) inside a silica tube furnace. X-ray diffraction results proved that by using this method a considerable amount of nitrogen was inserted into the catalyst structure at a relatively low temperature. Energy dispersive spectroscopy showed that the prepared catalyst should be oxidized carbonitride of titanium and/or tantalum. Heat treatment had a major effect on the onset potential by changing the crystallinity of the catalyst, so that the onset potential of titanium oxynitride increased from ca. 0.05 V to 0.65 V vs. NHE by increasing the temperature from 500 to 700 °C. Increasing the Ta concentration also led to a higher onset potential but lower ORR current. For instance, the onset potential for the ORR for tantalum oxynitride heat treated at 700 °C was ca. 0.85 V vs. NHE while this value was ca. 0.65 V vs. NHE for titanium oxynitride. However, the ORR current was 100 times smaller in tantalum oxynitride, most likely because of a low electrochemically active surface area. Electrochemical measurements suggested that an appropriate composition of titanium and tantalum was required to have both a good onset potential and ORR current by improving the catalytic activity and increasing the active surface area and electrical conductivity.

scholarly journals Oxygen Reduction Reaction on Polycrystalline Platinum: On the Activity Enhancing Effect of Polyvinylidene Difluoride

Surfaces ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 69-77
Author(s):  
Alessandro Zana ◽  
Gustav Wiberg ◽  
Matthias Arenz
Keyword(s):  
Mass Transport ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Surface Area ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Rotating Disk Electrode ◽  
Membrane Electrode ◽  
Active Surface Area ◽  
Polyvinylidene Difluoride

There have been several reports concerning the performance improving properties of additives, such as polyvinylidene difluoride (PVDF), to the membrane or electrocatalyst layer of proton exchange membrane fuel cells (PEMFC). However, it is not clear if the observed performance enhancement is due to kinetic, mass transport, or anion blocking effects of the PVDF. In a previous investigation using a thin-film rotating disk electrode (RDE) approach (of decreased complexity as compared to membrane electrode assembly (MEA) tests), a performance increase for the oxygen reduction reaction (ORR) could be confirmed. However, even in RDE measurements, reactant mass transport in the catalyst layer cannot be neglected. Therefore, in the present study, the influence of PVDF is re-examined by coating polycrystalline bulk Pt electrodes by PVDF and measuring ORR activity. The results on polycrystalline bulk Pt indicate that the effects of PVDF on the reaction kinetics and anion adsorption are limited, and that the observed performance increase on high surface area Pt/C most likely is due to an erroneous estimation of the electrochemical active surface area (ECSA) from CO stripping and Hupd.

Glancing Angle Deposited Platinum Nanorod Arrays for Oxygen Reduction Reaction

2011 ◽  
Vol 1311 ◽  
Author(s):  
Wisam J. Khudhayer ◽  
Nancy Kariuki ◽  
Deborah Myers ◽  
Ali Shaikh ◽  
Tansel Karabacak
Keyword(s):  
Oxygen Reduction Reaction ◽  
Single Crystal ◽  
Oxygen Reduction ◽  
Surface Area ◽  
Reduction Reaction ◽  
Active Surface Area ◽  
Nanorod Arrays ◽  
Electrocatalytic Oxygen Reduction ◽  
Glancing Angle ◽  
Orr Activity

ABSTRACTIn this work, we investigated the electrocatalytic oxygen reduction reaction (ORR) activity of vertically aligned, single-layer, carbon-free, and single crystal Pt nanorod arrays utilizing cyclic voltammetry (CV) and rotating-disk electrode (RDE) techniques. A glancing angle deposition (GLAD) technique was used to fabricate 200 nm long Pt nanorods, which corresponds to Pt loading of 0.16 mg/cm2, on glassy carbon (GC) electrode at a glancing angle of 85° as measured from the substrate normal. An electrode comprised of conventional carbon-supported Pt nanoparticles (Pt/C) was also prepared for comparison with the electrocatalytic ORR activity and stability of Pt nanorods. CV results showed that the Pt nanorod electrocatalyst exhibits a more positive oxide reduction peak potential compared to Pt/C, indicating that GLAD Pt nanorods are less oxophilic. In addition, a series of CV cycles in acidic electrolyte revealed that Pt nanorods are significantly more stable against electrochemically-active surface area loss than Pt/C. Moreover, room temperature RDE results demonstrated that GLAD Pt nanorods exhibit higher area-specific ORR activity than Pt/C. The enhanced electrocatalytic ORR activity of Pt nanorods is attributed to their larger crystallite size, single-crystal property, and the dominance of (110) crystal planes on the large surface area nanorods sidewalls, which has been found to be the most active plane for ORR. However, the Pt nanorods showed lower mass specific activity than the Pt/C electrocatalyst due to the large diameter of the Pt nanorods.

Microstructure and electrochemically active surface area of PtM/C electrocatalysts

2011 ◽  
Vol 47 (8) ◽  
pp. 933-939 ◽  
Author(s):  
V. E. Guterman ◽  
S. V. Belenov ◽  
T. A. Lastovina ◽  
E. P. Fokina ◽  
N. V. Prutsakova ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Surface ◽  
Active Surface Area ◽  
Electrochemically Active ◽  
Electrochemically Active Surface
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