Tracking Compression Changes in an Aqueous Electrolyte for Real-Time H2 and O2 Gas Evolution Quantification during Total Water Splitting Using BARDS

2020 ◽  
Vol 3 (2) ◽  
pp. 2000-2009
Author(s):  
Aaron Kang ◽  
Alanood Alkhraije ◽  
Seán McSweeney ◽  
Anas Alfarsi ◽  
Rizwan Ahmed ◽  
...  
Keyword(s):  
Real Time ◽  
Water Splitting ◽  
Aqueous Electrolyte ◽  
Gas Evolution ◽  
Total Water

Simultaneous Production of H2 and O2 With Rotary-Type Solar Reactor (Tokyo Tech Model) for Solar Hybrid Fuel

2008 ◽  
Author(s):  
Y. Tamaura ◽  
H. Kaneko ◽  
Y. Naganuma ◽  
S. Taku ◽  
K. Ouchi ◽  
...  
Keyword(s):  
Solid Solution ◽  
Water Splitting ◽  
Rotation Rate ◽  
Slow Rotation ◽  
Gas Evolution ◽  
Simultaneous Production ◽  
H2 Generation ◽  
Solar Reactor ◽  
Splitting Process ◽  
Rotary Type

The rotary-type solar reactor has been developed for solar hydrogen production with the two-step water splitting process using the reactive ceramic (Ni, Mn-ferrite). The rotary-type reactor has the rotating tubular cylinder covered on a reactive ceramic and dual reaction cells for O2-releasing and H2-generation reactions. The successive evolutions of O2 and H2 gases were observed in the O2 releasing and H2 generation reaction cells, respectively, with the prototype (small) reactor (diameter of cylinder ; 4cm). There is an upper limit for the rate of H2 gas evolution in the case of the prototype reactor because of the slow rotation rate in a small irradiation area. To confirm the practical operation of the rotary-type solar reactor with the two-step water splitting process for the simultaneous production of H2 and O2 gases, a scaled-up rotary-type solar reactor with 400cm2 of the irradiation area was fabricated (diameter; 50cm). The scaled-up reactor made of inner and outer short tubular cylinders (stainless steel) has a quartz glass window for the irradiation of reactive ceramic coated on the inner tubular cylinder (cylindrical rotor) and reaction cells were aligned in the sharing spaces between the inner and outer short tubular cylinders with gas sealing mechanisms. In the reactor, reactive ceramic coated on the inner tubular cylinder was heated up to 1800K by using the infrared imaging lamps (solar simulator) with thermal flux = 600kW/m2. The solid solution between YSZ and Ni-ferrite was used as reactive ceramic for the scaled-up reactor in order to prevent from sintering at a high temperature in the O2-releasing reaction, since the sintering of reactive ceramic resulted in lowering the yield of H2 gas evolution in the H2-generation reaction. The amounts of H2 and O2 gases evolved at the rotation rate of 0.3rpm were evaluated to 64cm3 and 30cm3 for 10min with the scaled-up rotary-type solar reactor, respectively, which were much larger than those with the prototype reactor. The simultaneous evolutions of H2 and O2 gases in the two-step water splitting process were repeated by employing the scaled-up reactor with the solid solution between YSZ and Ni-ferrite.

scholarly journals Decoupling Gas Evolution from Water-Splitting Electrodes

2019 ◽  
Author(s):  
Pablo Peñas ◽  
Peter van der Linde ◽  
Wouter Vijselaar ◽  
Devaraj van der Meer ◽  
Detlef Lohse ◽  
...  
Keyword(s):  
Water Splitting ◽  
Water Electrolysis ◽  
Gas Evolution ◽  
Dissolved Gas ◽  
Alkaline Water Electrolysis ◽  
Transport Models ◽  
Cell Potential ◽  
Transient Behaviour ◽  
Mass Transfer Processes ◽  
Novel Method

<div><div><div><p>Bubbles are known to hinder electrochemical processes in water-splitting electrodes. In this study, we present a novel method to promote gas evolution away from the electrode surface. We consider a ring microelectrode encircling a hydrophobic microcavity from which a succession of bubbles grows. The ring microelectrode, tested under alkaline water electrolysis conditions, does not suffer from bubble coverage. Consequently, the chronopotentiometric fluctuations of the cell are weaker than those associated with conventional microelectrodes. Herein, we provide fundamental understanding of the mass transfer processes governing the transient behaviour of the cell potential. With the help of numerical transport models, we demonstrate that bubbles forming at the cavity reduce the concentration overpotential by lowering the surrounding concentration of dissolved gas, but may also aggravate the ohmic overpotential by blocking ion-conduction pathways. The theoretical and experimental insight gained have relevant implications in the design of efficient gas-evolving electrodes.</p></div></div></div>

Enhancement of HER kinetics with RhNiFe for high-rate water electrolysis

2020 ◽  
Vol 10 (11) ◽  
pp. 3681-3693 ◽  
Author(s):  
Kannimuthu Karthick ◽  
Abdul Bashith Mansoor Basha ◽  
Abinaya Sivakumaran ◽  
Subrata Kundu
Keyword(s):  
Water Splitting ◽  
Water Electrolysis ◽  
High Rate ◽  
Total Water ◽  
Low Overpotential

The NiFeCHH is best for OER and poor for HER which by introducing Rh, showed total water splitting in KOH. It requires an ultra-low overpotential of just 36 mV at 50 mA cm−2 for HERs and 286 mV at 50 mA cm−2 for TWS.

scholarly journals TiO2-coated window for facilitated gas evolution in PEC solar water splitting

RSC Advances ◽  
2017 ◽  
Vol 7 (47) ◽  
pp. 29665-29671 ◽  
Author(s):  
Sérgio Miranda ◽  
António Vilanova ◽  
Tânia Lopes ◽  
Adélio Mendes
Keyword(s):  
Water Splitting ◽  
Gas Bubbles ◽  
Gas Evolution ◽  
Evolved Gas ◽  
Solar Water ◽  
Solar Water Splitting ◽  
Front Window ◽  
Pec Cells

TiO2 films were prepared for facilitating the evolved gas bubbles to slip over the front window of PEC cells resulting in a transparency improvement of up to 10%.

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