scholarly journals Nafion‐induced reduction of manganese and its impact on the electrocatalytic properties of a highly active MnFeNi oxide for bifunctional oxygen conversion

2021 ◽  
Author(s):  
Dulce Morales-Hernandez ◽  
Javier Villalobos ◽  
Mariya A. Kazakova ◽  
Jie Xiao ◽  
Marcel Risch
2018 ◽  
Vol 6 (46) ◽  
pp. 23445-23456 ◽  
Author(s):  
Xuan-Wen Gao ◽  
Junghoon Yang ◽  
Kyeongse Song ◽  
Wen-Bin Luo ◽  
Shi-Xue Dou ◽  
...  

FeCo alloy nanoparticles were nucleated onto graphitic carbon layers through the pyrolysis of polydopamine (PDA) sub-micrometer spheres to form a highly active electrocatalytic system that exhibits excellent oxygen conversion catalytic activity in both alkaline and acidic media.


2014 ◽  
Vol 2 (24) ◽  
pp. 9405-9411 ◽  
Author(s):  
Jiarui Wang ◽  
Frank E. Osterloh

The high activity of BiVO4/Co3O4 was attributed to the electrocatalytic properties of the Co3O4 cocatalyst and to the formation of a heterojunction at the BiVO4–Co3O4 interface.


2021 ◽  
Author(s):  
Dulce M. Morales ◽  
Javier Villalobos ◽  
Mariya A. Kazakova ◽  
Jie Xiao ◽  
Marcel Risch

Electrocatalysts for bifunctional oxygen reduction (ORR) and oxygen evolution reaction (OER) are commonly studied under hydrodynamic conditions, rendering the use of binders necessary to ensure the mechanical stability of the electrode films. The presence of a binder, however, may influence the properties of the materials under examination to an unknown extent. Herein, we investigate the impact of Nafion on a highly active ORR/OER catalyst consisting of MnFeNi oxide nanoparticles supported on multi-walled carbon nanotubes. Electrochemical studies revealed that, in addition to enhancing the mechanical stability and particle connectivity, Nafion poses a major impact on the ORR selectivity, which correlates with a decrease in the valence state of Mn according to X-ray absorption spectroscopy. These findings call for awareness regarding the use of electrode additives, since in some cases the extent of their impact on the properties of electrode films cannot be regarded as negligible.


2021 ◽  
Author(s):  
Dulce M. Morales ◽  
Javier Villalobos ◽  
Mariya A. Kazakova ◽  
Jie Xiao ◽  
Marcel Risch

Electrocatalysts for bifunctional oxygen reduction (ORR) and oxygen evolution reaction (OER) are commonly studied under hydrodynamic conditions, rendering the use of binders necessary to ensure the mechanical stability of the electrode films. The presence of a binder, however, may influence the properties of the materials under examination to an unknown extent. Herein, we investigate the impact of Nafion on a highly active ORR/OER catalyst consisting of MnFeNi oxide nanoparticles supported on multi-walled carbon nanotubes. Electrochemical studies revealed that, in addition to enhancing the mechanical stability and particle connectivity, Nafion poses a major impact on the ORR selectivity, which correlates with a decrease in the valence state of Mn according to X-ray absorption spectroscopy. These findings call for awareness regarding the use of electrode additives, since in some cases the extent of their impact on the properties of electrode films cannot be regarded as negligible.


Author(s):  
Alicja Urbaniak ◽  
Anna Skarpańska-Stejnborn

Abstract. The aim of the study was to review recent findings on the use of POM supplements in athletes of various disciplines and physically active participants. Eleven articles published between 2010 and 2018 were included, where the total number of investigated subjects was 176. Male participants constituted the majority of the group (n = 155), as compared to females (n = 21). 45% of research described was conducted on athletes, whereas the remaining studies were based on highly active participants. Randomised, crossover, double-blind study designs constituted the majority of the experimental designs used. POM supplementation varied in terms of form (pills/juice), dosage (50 ml–500 ml) and time of intervention (7 days–2 months) between studies. Among the reviewed articles, POM supplementation had an effect on the improvement of the following: whole body strength; feeling of vitality; acute and delayed muscle fatigue and soreness; increase in vessel diameter; blood flow and serum level of TAC; reduction in the rate of increase for HR, SBP, CK and LDH; support in the recovery of post-training CK, LDH, CRP and ASAT to their baseline levels; reduction of MMP2, MMP9, hsCRP and MDA; and increased activity of antioxidant enzymes (glutathione peroxidase and superoxide dismutase). In the majority of reviewed articles POM supplementation had a positive effect on a variety of parameters studied and the authors recommended it as a supplement for athletes and physically active bodies.


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