scholarly journals Effects of Antimony and Tin Additions in the Intermediate Ir1-x-y SnxSbyO2+0.5y Layer of Mn–Mo–Sn–O Electrocatalyst for Hydrogen Production from Seawater Electrolysis

2012 ◽  
Vol 27 ◽  
pp. 78-85
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Oxygen Evolution ◽  
Intermediate Layer ◽  
Electronic Conductivity ◽  
Titanium Substrate ◽  
Oxygen Production ◽  
Oxide Formation ◽  
Intermediate Layers ◽  
High Electronic Conductivity ◽  
Alternative Materials ◽  
Seawater Electrolysis

The oxygen production anode for seawater electrolysis is composed of two layers on the titanium substrate. The outermost layer is electrocatalysts of ?-MnO2 type Mn1-x-yMoxSnyO2+x triple oxides and the intermediate layer preventing insulating oxide formation on the titanium substrate is generally IrO2. Due to limited amount of iridium, alternative materials to the intermediate IrO2 having sufficient durability and conductivity at high potentials for anodic polarization are required. In this context, decrease in the amount of IrO2 by substitution with SnO2 and increase in the electronic conductivity of the intermediate layer by Sb2O5 addition is performed in this works. The additions of SnO2 with Sb2O5 to the intermediate layer of the Mn-Mo-Sn-O/Ir1–x–ySnxSbyO2+0.5y/Ti anodes was effective to decrease the use of IrO2, maintaining the high electronic conductivity of the intermediate Ir1–x–ySnxSbyO2+0.5y layer and the high activity of oxygen evolution in seawater electrolysis at pH 1 for about 1550 h. The oxygen evolution efficiency of the nanocrystalline ?-MnO2 type Mn-Mo-Sn-O/Ir1–x–ySnxSbyO2+0.5y/Ti anodes with 0.208 M Ir4+, 0.208-0.416 M Sn4+ and 0.104 M Sb5+ in the intermediate layers was about 98.5 % during electrolysis for about 1550 hours without any degradation in 0.5 M NaCl solution of pH 1 at 25°C.DOI: http://dx.doi.org/10.3126/jncs.v27i1.6664 J. Nepal Chem. Soc., Vol. 27, 2011 78-85 

scholarly journals The Effect of Antimony in the Intermediate IrO2-SnO2-Sb2O5 Oxide Layer on Titanium Substrate for Oxygen Evolution Mn1-x-yMoxSnyO2+x Anodes in Seawater Electrolysis

1970 ◽  
Vol 23 ◽  
pp. 21-32
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Oxide Layer ◽  
Oxygen Evolution ◽  
Intermediate Layer ◽  
Electronic Conductivity ◽  
Titanium Substrate ◽  
Coating Solution ◽  
Intermediate Layers ◽  
Initial Oxygen ◽  
Co2 Recycling ◽  
Seawater Electrolysis

An attempt is made to find out the optimal compositions for the intermediate oxide layer of IrO2-SnO2-Sb2O5 in preventing insulating titanium oxide formation on titanium substrate for the oxygen evolution Mn1-x-yMoxSnyO2+x anodes in electrolysis of 0.5 M NaCl of pH 1 at 1000 A.m-2. Effects of antimony and iridium in the intermediate IrO2-SnO2-Sb2O5 layer are discussed. The 75 % of the iridium content in the intermediate layer of the oxygen evolution anodes can be substituted by SnO2 and small amount of Sb2O5 to increase the electronic conductivity of the intermediate layer as well as the activity of the Mn1-x-yMoxSnyO2+x/IrO2-SnO2-Sb2O5/Ti anodes for seawater electrolysis at pH 1. Although Sb5+ addition is effective in decreasing the Ir4+ concentration in the intermediate layer of the anodes, the Ir1-x-ySnxSbyO2+0.5y intermediate layers with the Sb5+/Sn4+ between 0.125-0.285 in the coating solution showed excellent performance of the oxygen evolution efficiency. All the examined manganese-molybdenum-tin triple oxides, Mn1-x-yMoxSnyO2+x, prepared by anodic deposition on the IrO2-SnO2-Sb2O5-coated titanium substrate showed around 99% initial oxygen evolution efficiency at a current density of 1000 A.m-2 in 0.5 M NaCl of pH 1 at 25ºC.Keywords: global CO2 recycling, hydrogen production electrode, IrO2-SnO2-Sb2O5 layer, 0.5 M NaCl, titanium substrate.DOI: 10.3126/jncs.v23i0.2093J. Nepal Chem. Soc., Vol. 23, 2008/2009Page: 21-32

scholarly journals The Development of the Intermediate SnO2–Sb2O5 Layer on Titanium Substrate for Oxygen Evolution Anodes in Seawater Electrolysis

1970 ◽  
Vol 23 ◽  
pp. 54-64
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Oxygen Evolution ◽  
Intermediate Layer ◽  
Electronic Conductivity ◽  
Titanium Substrate ◽  
Coating Solution ◽  
High Electronic Conductivity ◽  
Initial Oxygen ◽  
Co2 Recycling ◽  
The Stability ◽  
Seawater Electrolysis

An attempt is made to replace the use of IrO2 by SnO2–Sb2O5 in the intermediate layer which is necessary to avoid the growth of insulating titanium oxide on the titanium substrate for oxygen evolution γ-MnO2 type Mn1-x-yMoxSnyO2+x anodes in seawater electrolysis. The manganese–molybdenum–tin triple oxides, Mn1-x-yMoxSnyO2+x, prepared by anodic deposition on the SnO2–Sb2O5-coated titanium substrate from MnSO4, Na2MoO4 and SnCl4 solutions showed around 98.6% initial oxygen evolution efficiency at a current density of 1000 Am-2 in 0.5 M NaCl of pH 1 at room temperature. In order to increase the stability of the anodes, coating at various times to form the intermediate SnO2–Sb2O5 layer with sufficient thickness on titanium substrate, was performed. The Mn1-x-yMoxSnyO2+x electrodes deposited on the intermediate layer formed from seven times coating showed about 98% oxygen evolution efficiency after 20 h electrolysis. A small addition of Sb2O5 to the intermediate layer (that is, Sb5+/Sn4+ = 0.124 in the coating solution) seems to be more effective to replace the use of IrO2 for high electronic conductivity and activity of oxygen evolution in seawater electrolysis. The formation of the double oxides of the intermediate SnO2–Sb2O5 layer after seven times coating seemed responsible for both high conductivity and stability of the Mn1-x-yMoxSnyO2+x anodes.Keywords: CO2 recycling, oxygen evolution electrode, intermediate SnO2–Sb2O5 layer, seawater electrolysis, titanium substrate.DOI: 10.3126/jncs.v23i0.2097J. Nepal Chem. Soc., Vol. 23, 2008/2009 Page: 54-64 

scholarly journals Effects of Ir, Sn and Sb in the intermediate Ir1-x-y SnxSbyO2+0.5y layer of Mn-Mo-Sn-O electrocatalyst for hydrogen production

1970 ◽  
Vol 7 ◽  
pp. 79-84
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Hydrogen Production ◽  
Oxygen Evolution ◽  
High Current Density ◽  
Titanium Substrate ◽  
Plant Science ◽  
High Current ◽  
Nacl Solution ◽  
Co2 Recycling ◽  
Seawater Electrolysis ◽  
Key Words Oxygen

An attempt is made to reduce the use of IrO2 by the IrO2-SnO2-Sb2O5 intermediate layer which is necessary to avoid the growth of insulating titanium oxide on the titanium substrate for oxygen evolution ã-MnO2 type nanocrystalline Mn-Mo-Sn-O/Ir1-x-ySnxSbyO2+0.5y/Ti anodes in 0.5 M NaCl solution of pH 1 at 25°C. These electrodeposited Mn-Mo-Sn-based triple oxide anodes showed about 97.2-98.6 % oxygen evolution efficiency at high current density of 1000 A.m-2 in 0.5 M NaCl solution of pH 1 at 25°C. The high oxygen evolution efficiency of these triple oxide electrocatalysts maintained during prolonged electrolysis and even after the electrolysis for about two months. Key-words: Oxygen evolution efficiency; electrocatalyst; seawater electrolysis; CO2 recycling; XRD DOI: 10.3126/botor.v7i0.4387Botanica Orientalis - Journal of Plant Science (2010) 7: 79-84

scholarly journals A Superaerophobic Bimetallic Selenides Heterostructure for Efficient Industrial-Level Oxygen Evolution at Ultra-High Current Densities

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiaxin Yuan ◽  
Xiaodi Cheng ◽  
Hanqing Wang ◽  
Chaojun Lei ◽  
Sameer Pardiwala ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Active Sites ◽  
Electronic Conductivity ◽  
Three Dimensional ◽  
Active Surface ◽  
Alkaline Media ◽  
Active Surface Area ◽  
High Current ◽  
High Electronic Conductivity ◽  
Current Densities

AbstractCost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction (OER) are critical to the energy crisis and environmental pollution. Herein, we report a superaerophobic three dimensional (3D) heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy (NiSe2/NiFe2Se4@NiFe) prepared by a thermal selenization procedure. In this unique 3D heterostructure, numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~ 100 nm are grown on NiFe alloy in a uniform manner. Profiting by the large active surface area and high electronic conductivity, the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media, outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm−2, respectively, which is among the most active Ni/Fe-based selenides, and even superior to the benchmark Ir/C catalyst. The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.

Spindle Spinel CoFeCoO4 Microparticles/rGO as an Oxygen Reduction and Oxygen Evolution Catalyst

NANO ◽  
2019 ◽  
Vol 14 (04) ◽  
pp. 1950043 ◽  
Author(s):  
Bowen Wang ◽  
Nian Tao ◽  
Junchen Liu ◽  
Hao Wang ◽  
Yinxiao Du ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Oxygen Evolution ◽  
Electronic Conductivity ◽  
Reduction Reaction ◽  
Spinel Type ◽  
High Electronic Conductivity ◽  
Catalytic Sites ◽  
Catalytic Stability ◽  
Orr Activity ◽  
Effective Charge Transfer

The representative spinel-type materials AB2O4 (both A and B are transition metals) electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have been investigated and significant improvements have been achieved in the activity and durability for ORR and OER in the alkaline solution. But CoFeCoO4 was not explored widely like ZnCo2O4 (or NiCo2O[Formula: see text] as the ORR electrocatalyst for its relatively complicated atomic site occupation. CoFeCoO4 has a typical cubic spinel structure with Co[Formula: see text] in the tetrahedron and Co[Formula: see text] and Fe[Formula: see text] in the octahedron. A mixture of Co[Formula: see text] and Fe[Formula: see text] in the B site makes the oxide have a wider overlap between transition metal 3d orbit and O 2p orbit, which can lead to an effective charge transfer in the rate-determining steps of ORR process and then enhance the ORR activity. The high electronic conductivity and specific surface area of rGO can accelerate charger transfer and provide more catalytic sites, which would contribute to a faster ORR process. In this work, the porous spindle CoFeCoO4 microparticles which were synthesized by hydrothermal technology, were assembled on the rGO surface to obtain the CoFeCoO4/rGO composite, which exhibited enhanced ORR activity and catalytic stability comparable to that of Pt/C. On the other hand, the OER catalytic activity of the prepared samples was also studied to explore the potential of CoFeCoO4/rGO as a bifunctional oxygen catalyst.

High-performance anion exchange membrane alkaline seawater electrolysis

2021 ◽  
Author(s):  
Yoo Sei Park ◽  
Jooyoung Lee ◽  
Myeong-Je Jang ◽  
Juchan Yang ◽  
Jae Hoon Jeong ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Performance ◽  
Anion Exchange Membrane ◽  
Hydrogen Energy ◽  
Highly Active ◽  
Production Of Hydrogen ◽  
Exchange Membrane ◽  
Seawater Electrolysis

Seawater electrolysis is a promising technology for the production of hydrogen energy and seawater desalination. To produce hydrogen energy through seawater electrolysis, highly active electrocatalysts for the oxygen evolution reaction...

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