scholarly journals Energy-saving electrolytic γ-MnO2 generation: non-noble metal electrocatalyst gas diffusion electrode as cathode in acid solution

RSC Advances ◽  
2019 ◽  
Vol 9 (43) ◽  
pp. 24816-24821
Author(s):  
Jing Tang ◽  
Hui Min Meng ◽  
Mei Yang Ji

Co3O4/FLG was used as a nanocatalyst to catalyze the ORR in the electrodeposition of MnO2. The proposed Co3O4/FLG nanocomposite GDE exhibited a high activity of 0.9 V at a current density of 100 A m−2.

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhanwu Lei ◽  
Wenbin Cai ◽  
Yifei Rao ◽  
Kuan Wang ◽  
Yuyuan Jiang ◽  
...  

AbstractSingle-atom catalysts (SACs) have attracted tremendous research interests in various energy-related fields because of their high activity, selectivity and 100% atom utilization. However, it is still a challenge to enhance the intrinsic and specific activity of SACs. Herein, we present an approach to fabricate a high surface distribution density of iridium (Ir) SAC on nickel-iron sulfide nanosheet arrays substrate (Ir1/NFS), which delivers a high water oxidation activity. The Ir1/NFS catalyst offers a low overpotential of ~170 mV at a current density of 10 mA cm−2 and a high turnover frequency of 9.85 s−1 at an overpotential of 300 mV in 1.0 M KOH solution. At the same time, the Ir1/NFS catalyst exhibits a high stability performance, reaching a lifespan up to 350 hours at a current density of 100 mA cm−2. First-principles calculations reveal that the electronic structures of Ir atoms are significantly regulated by the sulfide substrate, endowing an energetically favorable reaction pathway. This work represents a promising strategy to fabricate high surface distribution density single-atom catalysts with high activity and durability for electrochemical water splitting.


2017 ◽  
Vol 5 (16) ◽  
pp. 7305-7308 ◽  
Author(s):  
Libin Yang ◽  
Danni Liu ◽  
Shuai Hao ◽  
Rongmei Kong ◽  
Abdullah M. Asiri ◽  
...  

As a durable catalyst electrode, a cobalt-borate nanosheet array on a Ti mesh shows high activity for water oxidation in 0.1 M K-Bi (pH: 9.2), achieving a geometrical catalytic current density of 10 mA cm−2 at an overpotential of 469 mV.


2010 ◽  
Vol 61 (1) ◽  
pp. 107-118
Author(s):  
W. Y. Xu ◽  
P. Li ◽  
B. Dong

To be best of our knowledge, this study is one of the first investigations to be performed into the potential benefits of gas diffusion electrode (GDE) system in controlling inactivation of E. coli. This study mainly focused on the dual electrodes disinfection with gas diffusion cathode, using Escherichia coli as the indicator microorganisms. The effects of Pt load WPt and the pore-forming agent content WNH4HCO3 in GDE, operating conditions such as pH value, oxygen flow rate QO2, salt content and current density on the disinfection were investigated, respectively. The experimental results showed that the disinfection improved with increasing Pt load WPt, but its efficiency at Pt load of 3‰ was equivalent to that at Pt load of 4‰. Addition of the pore-forming agent in the appropriate amount improved the disinfection while drop of pH value resulted in the rapid rise of the germicidal efficacy and the disinfection shortened with increasing oxygen flow rate QO2. The system is more suitable for highly salt water. The germicidal efficacy increased with current density. However, the accelerating rate was different: it first increased with the current density, then decreased, and reached a maximum at current density of 6.7–8.3 mA/cm2. The germicidal efficacy in the cathode compartment was about the same as in the anode compartment indicating the contribution of direct oxidation and indirect treatment of E. coli by the hydroxyl radical was similar to the oxidative indirect effect of the generated H2O2. This technology is expensive in operating cost, further research is required to advance the understanding and reduce the operating cost of this technology.


2020 ◽  
Vol 44 (5) ◽  
pp. 1227-1243
Author(s):  
Hande UNGAN ◽  
Ayşe BAYRAKÇEKEN YURTCAN

Water management is one of the obstacles in the development and commercialization of proton exchange membrane fuel cells (PEMFCs). Sufficient humidification of the membrane directly affects the PEM fuel cell performance. Therefore, 2 different hydrophobic polymers, polydimethylsiloxane (PDMS) and (3-Aminopropyl) triethoxysilane (APTES), were tested at different percentages (5, 10, and 20 wt.%) in the catalyst layer. The solution was loaded onto the surface of a 25 BC gas diffusion layer (GDL) via the spraying method. The performance of the obtained fuel cells was compared with the performance of the commercial catalyst. Characterizations of each surface, including different amounts of PDMS and APTES, were performed via scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analyses. Molecular bond characterization was examined via Fourier transform infrared spectroscopy (FTIR) analysis and surface hydrophobicity was measured via contact angle measurements. The performance of the fuel cells was evaluated at the PEM fuel cell test station and the 2 hydrophobic polymers were compared. Surfaces containing APTES were found to be more hydrophobic. Fuel cells with PDMS performed better when compared to those with APTES. Fuel cells with 5wt.% APTES with a current density of 321.31 mA/cm2and power density of 0.191 W/cm2, and 10wt.% PDMS with a current density of 344.52 mA/cm2and power density of 0.205 W/cm2 were the best performing fuel cells at 0.6V.


2014 ◽  
Vol 496-500 ◽  
pp. 159-162
Author(s):  
Yan Hou ◽  
Fan Gong Kong ◽  
Shou Juan Wang ◽  
Gui Hua Yang

Hydrogen peroxide production via cathodic reduction of oxygen on self-made gas diffusion electrode was investigated in an undivided electrochemical system. The effects of mass ratio between graphite and PTFE in cathode, the calcination temperature, current density, pH, and plate distance on hydrogen peroxide generation were discussed. The results showed that the self-made gas diffusion cathode had high catalyze capacity for production of hydrogen peroxide using cathodic oxygen-reducing reaction. The hydrogen peroxide concentration could reach 80.52 mg·L- 1 within 2 h. The optimal conditions for this system are as follows: mass ratio of graphite to PTFE in cathode, 21, calcination temperature, 300 °C, current density,4.69mA/cm2, pH 13.0, and the distance between anode and cathode, 8cm. The high concentration of hydrogen peroxide generated gives a promising application of this novel gas diffusion electrode system in pulp bleaching and waste-water treatment.


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