scholarly journals Application of platinum-cobalt-boron as the anode material for sodium borohydride-hydrogen peroxide fuel cells

Chemija ◽  
2018 ◽  
Vol 29 (4) ◽  
Author(s):  
Aldona Balčiūnaitė ◽  
Zita Sukackienė ◽  
Loreta Tamašauskaitė-Tamašiūnaitė ◽  
Rimantas Vaitkus ◽  
Eugenijus Norkus

The electroless deposition and galvanic displacement methods were used for the fabrication of cobalt–boron (CoB) catalysts modified with small amounts of platinum crystallites in the range of 9.8 to 14.4 μgPt cm–2. The prepared catalysts were studied as the anode materials for direct borohydride–hydrogen peroxide (NaBH4/H2O2) fuel cells at temperatures of 25–55°C. Polarization curves have been recorded with the aim to evaluate the fuel cell performance using the prepared CoB and that modified with Pt crystallites as the anode catalysts. For all catalysts (pure CoB and PtCoB) investigated, the peak power density values increase consecutively with the increment in temperature from 25°C up to 55°C. The values from 86–146 mV cm–2 and 146–234 mV cm–2 were determined for pure CoB and PtCoB catalysts, respectively. The highest specific peak power density of 21.5 kWgPt–1 was achieved at 55°C temperature when the PtCoB catalyst with the Pt loading of 9.8 μgPtcm–2 was employed as the anode catalyst in the NaBH4/H2O2 single fuel cell.

2020 ◽  
Vol 56 (42) ◽  
pp. 5669-5672
Author(s):  
Zhanna Tatus-Portnoy ◽  
Anna Kitayev ◽  
Thazhe Veettil Vineesh ◽  
Ervin Tal-Gutelmacher ◽  
Miles Page ◽  
...  

Herein, we report a Ru-rich anode catalyst for alkaline exchange membrane fuel cells. At 80 °C, a fuel cell with a RuPdIr/C anode and Ag based cathode attained a peak power density close to 1 W cm−2 with 0.2 mg cm−2 anode loading in comparison to 0.77 W cm−2 for the cell tested with the same metal loading of Pt.


Author(s):  
S. W. Cha ◽  
S. J. Lee ◽  
Y. I. Park ◽  
F. B. Prinz

This paper presents a study on the transport phenomena related to gas flow through fuel cell micro-channels, specifically the impact of dimensional scale on the order of 100 microns and below. Especially critical is the ability to experimentally verify model predictions, and this is made efficiently possible by the use of structural photopolymer (SU-8) to directly fabricate functional fuel cell micro-channels. The design and analysis components of this investigation apply 3-D multi-physics modeling to predict cell performance under micro-channel conditions. Interestingly, the model predicts that very small channels (specifically 100 microns and below) result in a significantly higher peak power density than larger counterparts. SU-8 micro-channels with different feature sizes have been integrated into fuel cell prototypes and tested for comparison against model predictions. The results not only demonstrate that the SU-8 channels with metal current collector show quite appreciable performance, but also provide experimental verification of the merits of channel miniaturization. As predicted, the performance in terms of peak power density increases as the feature size of the channel decreases, even though the pressure drop is higher in the more narrow channels. So it has been observed both theoretically and experimentally that cell performance shows an improving trend with micro-channels, and design optimization for miniature fuel cell provides a powerful method for increasing power density.


2012 ◽  
Vol 512-515 ◽  
pp. 1520-1524 ◽  
Author(s):  
Yu Zhao ◽  
Xiao Bin Wang ◽  
Peng Li ◽  
Yan Ping Sun

Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), power density and anode potential are used to characterize the mediator microbial fuel cell at different methylene blue (MB) concentrations. At lower MB concentration between 9.98×10-3 mmol/L and 1.66×10-1 mmol/L, the increased power density is enabled by using high mediator concentrations. Higher peak power density of 159.6 mw/m2 is observed compared with the peak power density of 36.0 mw/m2. But MB at too high concentration is disadvantageous to the perform of MFC. At the MB concentration of 2.50×10-1 mmol/L, the peak power output is just 128.4 mw/m2, which is lower than 159.6 mw/m2 at MB concentration of 1.66×10-1 mmol/L.


Author(s):  
Pinchas Schechner ◽  
Eugenia Bubis ◽  
Hana Faiger ◽  
Eyal Zussman ◽  
Ehud Kroll

This work adds more experimental evidence regarding the feasibility of using glucose to fuel fuel-cells with anodes that have a high area-to-volume ratio. Electrospinning was used to fabricate sub-micrometer size fibrous electrocatalytic anode membranes for the oxidation of glucose in an alkaline fuel cell (AFC). The fibers of the membranes were made of polyacrylonitrile (PAN) and coated with silver by electroless plating. The anodes were tested while installed in a membranless fuel cell. The results presented include the open circuit voltage, OCV, the polarization curve, the power density as a function of the current density, and the peak power density, PPD. The measurements were performed with constant concentrations of glucose, 0.8 M, and KOH electrolyte solution, 1M. The performance of the anodes was found to improve as the diameter of the silver-plated fibers decreased. The highest PPD of 0.28 mW/cm2 was obtained with an anode made of plated fibers having a mean fiber diameter of 130 nanometers. We conclude from the results that saccharides in general, and glucose in particular, can serve as fuels for fuel cells, and that silver-plated polymeric electrospun electrodes have advantages due to their large surface area.


2007 ◽  
Vol 60 (7) ◽  
pp. 528 ◽  
Author(s):  
Jason M. Tang ◽  
Kurt Jensen ◽  
Wenzhen Li ◽  
Mahesh Waje ◽  
Paul Larsen ◽  
...  

A simple and promising fuel-cell architecture is demonstrated using a carbon nanotube free-standing membrane (CNTFSM) made from Pt supported on purified single-walled carbon nanotubes (Pt/SWNT), which act as the catalyst layer in a hydrogen proton exchange membrane fuel cell without the need for Nafion in the catalyst layer. The CNTFSM made from Pt/SWNT at a loading of 0.082 mg Pt cm–2 exhibits higher performance with a peak power density of 0.675 W cm–2 in comparison with a commercially available E-TEK electrocatalyst made of Pt supported on XC-72 carbon black, which had a peak power density of 0.395 W cm–2 at a loading of 0.084 mg Pt cm–2 also without Nafion in the catalyst layer.


2015 ◽  
Vol 3 (4) ◽  
pp. 1410-1416 ◽  
Author(s):  
L. Zeng ◽  
T. S. Zhao ◽  
L. An

The use of supportless Ag NWs enabled the H2/O2 AEMFC to yield a peak power density of 164 mW cm−2.


Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 349
Author(s):  
Daniel Herranz ◽  
Roxana E. Coppola ◽  
Ricardo Escudero-Cid ◽  
Kerly Ochoa-Romero ◽  
Norma B. D’Accorso ◽  
...  

Crosslinked membranes have been synthesized by a casting process using polybenzimidazole (PBI) and poly(vinyl benzyl chloride) (PVBC). The membranes were quaternized with 1,4-diazabicyclo[2.2.2]octane (DABCO) to obtain fixed positive quaternary ammonium groups. XPS analysis has showed insights into the changes from crosslinked to quaternized membranes, demonstrating that the crosslinking reaction and the incorporation of DABCO have occurred, while the 13C-NMR corroborates the reaction of DABCO with PVBC only by one nitrogen atom. Mechanical properties were evaluated, obtaining maximum stress values around 72 MPa and 40 MPa for crosslinked and quaternized membranes, respectively. Resistance to oxidative media was also satisfactory and the membranes were evaluated in single direct ethanol fuel cell. PBI-c-PVBC/OH 1:2 membrane obtained 66 mW cm−2 peak power density, 25% higher than commercial PBI membranes, using 0.5 bar backpressure of pure O2 in the cathode and 1 mL min−1 KOH 2M EtOH 2 M aqueous solution in the anode. When the pressure was increased, the best performance was obtained by the same membrane, reaching 70 mW cm−2 peak power density at 2 bar O2 backpressure. Based on the characterization and single cell performance, PBI-c-PVBC/OH membranes are considered promising candidates as anion exchange electrolytes for direct ethanol fuel cells.


RSC Advances ◽  
2020 ◽  
Vol 10 (49) ◽  
pp. 29119-29127
Author(s):  
Yuehan Chen ◽  
Shuping Wang ◽  
Zhoupeng Li

Co–pyrrole/MPC was synthesized by using pyrrole and cobalt nitrate as nitrogen and metal source, which enabled a higher peak power density than the commercialized 28.6 wt% Pt/XC72 in DBFC.


2020 ◽  
Vol 45 (27) ◽  
pp. 13929-13938 ◽  
Author(s):  
Snezana M. Brkovic ◽  
Milica P. Marceta Kaninski ◽  
Petar Z. Lausevic ◽  
Aleksandra B. Saponjic ◽  
Aleksandra M. Radulovic ◽  
...  

Author(s):  
Nader Mokhtarian ◽  
Mostafa Ghasemi ◽  
Wan Ramli Wan Daud ◽  
Manal Ismail ◽  
Ghasem Najafpour ◽  
...  

The characteristics of four new proton-conducting membranes, Nafion112/polyaniline composite membranes of various compositions, are studied for application as membrane separators in microbial fuel cells. The composite membranes are made by immersing Nafion-112 membranes in a solution containing aniline for different immersion times. The presence of polyaniline and sulfonic functional groups in the composite membranes is confirmed by means of Fourier transform infrared analysis while their surface roughness is determined by using atomic force microscopy prior to microbial fuel cell operation. Biofouling on the membranes' surface is also examined by using a scanning electron microscope after microbial fuel cell operation. The polarization curves and, hence, the power density curves are measured by varying the load's resistance. The power density of the microbial fuel cell with the Nafion/polyaniline composite membranes improves significantly as the amount of polyaniline increases because the interaction between sulfonic groups in the Nafion matrix and polyaniline in the polyaniline domains increases proton conductivity. However, it declines after more polyaniline is added because of less conjugated bonding of polyaniline and sulfonic acid groups for larger polyaniline domains in the Nafion matrix. The voltage overpotential is also smaller as the amount of polyaniline increases. Biofouling also decreases with increasing polyaniline in the Nafion/polyaniline composite membranes because they have smoother surfaces than Nafion membranes. The results show that the maximum power generated by the microbial fuel cells with Nafion112-polyaniline composite membrane is 124.03 mV m−2 with a current density of 454.66 mA m−2, which is approximately more than ninefold higher than that of microbial fuel cells with neat Nafion-112. It can be concluded that the power density of the microbial fuel cell can be increased by modifying the Nafion membrane separators with more conductive polymers that are less susceptible to biofouling to improve its proton conductivity.


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