Ni-Based Electrocatalyst for Water Oxidation Developed In-Situ in a HCO3−/CO2System at Near-Neutral pH

2014 ◽  
Vol 4 (9) ◽  
pp. 1301929 ◽  
Author(s):  
Khurram Saleem Joya ◽  
Yasir F. Joya ◽  
Huub J. M. de Groot
Keyword(s):  
Water Oxidation ◽  
Neutral Ph

scholarly journals In Situ EPR Characterization of a Cobalt Oxide Water Oxidation Catalyst at Neutral pH

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 926 ◽  
Author(s):  
Yury Kutin ◽  
Nicholas Cox ◽  
Wolfgang Lubitz ◽  
Alexander Schnegg ◽  
Olaf Rüdiger
Keyword(s):  
Cobalt Oxide ◽  
Water Oxidation ◽  
Large Scale ◽  
Low Cost ◽  
Operating Conditions ◽  
Oxidation Catalyst ◽  
O2 Evolution ◽  
Ligand Field ◽  
Neutral Ph

Here we report an in situ electron paramagnetic resonance (EPR) study of a low-cost, high-stability cobalt oxide electrodeposited material (Co-Pi) that oxidizes water at neutral pH and low over-potential, representing a promising system for future large-scale water splitting applications. Using CW X-band EPR we can follow the film formation from a Co(NO3)2 solution in phosphate buffer and quantify Co uptake into the catalytic film. As deposited, the film shows predominantly a Co(II) EPR signal, which converts into a Co(IV) signal as the electrode potential is increased. A purpose-built spectroelectrochemical cell allowed us to quantify the extent of Co(II) to Co(IV) conversion as a function of potential bias under operating conditions. Consistent with its role as an intermediate, Co(IV) is formed at potentials commensurate with electrocatalytic O2 evolution (+1.2 V, vs. SHE). The EPR resonance position of the Co(IV) species shifts to higher fields as the potential is increased above 1.2 V. Such a shift of the Co(IV) signal may be assigned to changes in the local Co structure, displaying a more distorted ligand field or more ligand radical character, suggesting it is this subset of sites that represents the catalytically ‘active’ component. The described spectroelectrochemical approach provides new information on catalyst function and reaction pathways of water oxidation.

Calcium containing iron oxide as an efficient and robust catalyst in (photo-)electrocatalytic water oxidation at neutral pH

2018 ◽  
Vol 2 (1) ◽  
pp. 271-279 ◽  
Author(s):  
Hung-Chun Chiu ◽  
Wei-Hsiang Huang ◽  
Liang-Ching Hsu ◽  
Yan-Gu Lin ◽  
Yi-Hsuan Lai ◽  
...  
Keyword(s):  
Iron Oxide ◽  
High Activity ◽  
Water Oxidation ◽  
Iron Phosphate ◽  
Neutral Ph ◽  
Amorphous Nature

The amorphous nature and in situ formation of iron phosphate render CaFeOx with high activity and stability for the OER at neutral pH.

Capturing Manganese Oxide Intermediates in Electrochemical Water Oxidation at Neutral pH by In Situ Raman Spectroscopy

2021 ◽  
Vol 133 (9) ◽  
pp. 4723-4731
Author(s):  
Kang Hee Cho ◽  
Sunghak Park ◽  
Hongmin Seo ◽  
Seungwoo Choi ◽  
Moo Young Lee ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Manganese Oxide ◽  
Water Oxidation ◽  
In Situ Raman Spectroscopy ◽  
In Situ Raman ◽  
Neutral Ph

Capturing Manganese Oxide Intermediates in Electrochemical Water Oxidation at Neutral pH by In Situ Raman Spectroscopy

2021 ◽  
Vol 60 (9) ◽  
pp. 4673-4681
Author(s):  
Kang Hee Cho ◽  
Sunghak Park ◽  
Hongmin Seo ◽  
Seungwoo Choi ◽  
Moo Young Lee ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Manganese Oxide ◽  
Water Oxidation ◽  
In Situ Raman Spectroscopy ◽  
In Situ Raman ◽  
Neutral Ph

scholarly journals In situ evolution of surface Co2CrO4 to CoOOH/CrOOH by electrochemical method: Toward boosting electrocatalytic water oxidation

2021 ◽  
Vol 42 (7) ◽  
pp. 1096-1101 ◽  
Author(s):  
Jinxiu Zhao ◽  
Xiang Ren ◽  
Xu Sun ◽  
Yong Zhang ◽  
Qin Wei ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Electrochemical Method

Reduction of adsorbable organically bound halogens (AOX) formation at near-neutral pH chlorine dioxide bleaching of softwood kraft pulp

Holzforschung ◽  
2020 ◽  
Vol 74 (6) ◽  
pp. 597-604
Author(s):  
Sara Starrsjö ◽  
Olena Sevastyanova ◽  
Peter Sandström ◽  
Juha Fiskari ◽  
Maria Boman ◽  
...  
Keyword(s):  
Chlorine Dioxide ◽  
High Selectivity ◽  
Bicarbonate Buffer ◽  
Neutral Ph ◽  
Elemental Chlorine ◽  
Pulp Viscosity ◽  
Softwood Kraft Pulp ◽  
New Type ◽  
Adsorbable Organically Bound Halogens

AbstractRecently, a new type of bleaching sequence, Elemental Chlorine Free (ECF) light with one D stage, has been developed. It combines the efficiency and high selectivity of chlorine dioxide (ClO2) bleaching with more environmental friendly oxygen based bleaching chemicals. This work examines the effect of pH on the formation of adsorbable organically bound halogens (AOX) in an intermediate D stage – a single ClO2 stage at the middle of an ECF light bleaching sequence. Carbon dioxide (CO2) is used to generate a bicarbonate buffer in situ, stabilizing the pH during the bleaching. Near-neutral pH is hypothesized to decrease the formation of strongly chlorinating species, so that the AOX formation is reduced. The results indicate that a near-neutral pH D stage can reduce the AOX content in the effluents with up to 30%. The ISO brightness was unchanged to a lower ClO2 consumption. The pulp viscosity was slightly higher after near-neutral pH D stage, but to its disadvantage a lesser delignification and removal of HexA was obtained. The degradation of HexA correlated well with the AOX, affirming earlier theories that HexA has a major impact on the AOX formation. The higher amounts of residual HexA and lignin resulted in more thermal yellowing of the pulps bleached with a near-neutral pH D stage.

In Situ Photoluminescence Analysis of GaN Photoanode during Water Oxidation

2021 ◽  
Author(s):  
Tsutomu Minegishi ◽  
Soraya Shizumi ◽  
Oguz Ciftci ◽  
Tatsuro Endo ◽  
Yuki Imazeki ◽  
...  
Keyword(s):  
Water Oxidation

In Situ Formation of Efficient Cobalt-Based Water Oxidation Catalysts from Co2+-Containing Tungstate and Molybdate Solutions

2015 ◽  
Vol 10 (10) ◽  
pp. 2228-2233 ◽  
Author(s):  
Biaobiao Zhang ◽  
Xiujuan Wu ◽  
Fei Li ◽  
Fengshou Yu ◽  
Yong Wang ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Oxidation Catalysts ◽  
In Situ Formation
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