scholarly journals Ni-Fe phosphide deposited carbon felt as free-standing bifunctional catalyst electrode for urea electrolysis

2021 ◽  
Author(s):  
Woo Hyun Yun ◽  
Gautam Das ◽  
Bohyeon Kim ◽  
Bang Ju Park ◽  
Hyon Hee Yoon ◽  
...  
Keyword(s):  
Water Electrolysis ◽  
Bifunctional Catalyst ◽  
Electrolysis Cell ◽  
Carbon Felt ◽  
Free Standing ◽  
Cell Potential ◽  
Urea Electrolysis ◽  
A Cell ◽  
A Current ◽  
Catalyst Electrode

Abstract A free-standing catalyst electrode for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) in a urea electrolysis cell was synthesized by electroplating a Ni-Fe alloy onto carbon felt, followed by phosphidation (P-NiFe@CF). The prepared P-NiFe@CF catalyst consisted of Ni5P4, NiP2, and FeP with 3D flower-like P-NiFe architecture on CF. P-NiFe@CF exhibited excellent electrocatalytic activity for the UOR (demanding only 1.44 V (vs. RHE) to achieve 200 mA cm −2), and for the HER with a low overpotential of 0.065 V (vs. RHE) at 10 mA cm−2, indicating its feasibility as a bifunctional catalyst electrode for urea electrolysis. A urea electrolysis cell with P-NiFe@CF as both the free-standing anode and cathode generated a current density of 10 mA cm−2 at a cell potential of 1.42 V (vs. RHE), which is considerably lower than that of water electrolysis, and also lower than previously reported values. The results indicate that the P-NiFe@CF catalyst electrodes can be used as free-standing bifunctional electrodes for urea electrolyzers.

scholarly journals Ni–Fe phosphide deposited carbon felt as free-standing bifunctional catalyst electrode for urea electrolysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Woo Hyun Yun ◽  
Gautam Das ◽  
Bohyeon Kim ◽  
Bang Ju Park ◽  
Hyon Hee Yoon ◽  
...  
Keyword(s):  
Water Electrolysis ◽  
Bifunctional Catalyst ◽  
Electrolysis Cell ◽  
Carbon Felt ◽  
Free Standing ◽  
Cell Potential ◽  
Urea Electrolysis ◽  
A Cell ◽  
A Current ◽  
Catalyst Electrode

AbstractA free-standing catalyst electrode for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) in a urea electrolysis cell was synthesized by electroplating a Ni–Fe alloy onto carbon felt, followed by phosphidation (P-NiFe@CF). The prepared P-NiFe@CF catalyst consisted of Ni5P4, NiP2, and FeP with 3D flower-like P-NiFe architecture on CF. P-NiFe@CF exhibited excellent electrocatalytic activity for the UOR (demanding only 1.39 V (vs. RHE) to achieve 200 mA cm−2), and for the HER with a low overpotential of 0.023 V (vs. RHE) at 10 mA cm−2, indicating its feasibility as a bifunctional catalyst electrode for urea electrolysis. A urea electrolysis cell with P-NiFe@CF as both the free-standing anode and cathode generated a current density of 10 mA cm−2 at a cell potential of 1.37 V (vs. RHE), which is considerably lower than that of water electrolysis, and also lower than previously reported values. The results indicate that the P-NiFe@CF catalyst electrodes can be used as free-standing bifunctional electrodes for urea electrolyzers.

Ultrathin cobalt phosphide nanosheets as efficient bifunctional catalysts for a water electrolysis cell and the origin for cell performance degradation

2016 ◽  
Vol 18 (8) ◽  
pp. 2287-2295 ◽  
Author(s):  
Jinfa Chang ◽  
Liang Liang ◽  
Chenyang Li ◽  
Minglei Wang ◽  
Junjie Ge ◽  
...  
Keyword(s):  
Water Electrolysis ◽  
Bifunctional Catalyst ◽  
Performance Degradation ◽  
Cell Performance ◽  
Electrolysis Cell ◽  
Bifunctional Catalysts ◽  
Basic Solution ◽  
Cobalt Phosphide

Ultrathin CoP nanosheets are prepared by a green and facile approach and found to be an effective and robust bifunctional catalyst material for OER and HER in a basic solution.

High-performance urea electrolysis towards less energy-intensive electrochemical hydrogen production using a bifunctional catalyst electrode

2017 ◽  
Vol 5 (7) ◽  
pp. 3208-3213 ◽  
Author(s):  
Danni Liu ◽  
Tingting Liu ◽  
Lixue Zhang ◽  
Fengli Qu ◽  
Gu Du ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Water Splitting ◽  
Hydrogen Evolution Reaction ◽  
Oxidation Reaction ◽  
High Performance ◽  
Pure Water ◽  
Bifunctional Catalyst ◽  
Carbon Cloth ◽  
Urea Electrolysis ◽  
Catalyst Electrode

Ni2P nanoflake arrays on carbon cloth act as an efficient and durable catalyst electrode for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). Its two-electrode alkaline electrolyzer needs 1.35 V for 50 mA cm−2, which is 0.58 V less than that required for pure water splitting.

Design and synthesis of integrally structured Ni3N nanosheets/carbon microfibers/Ni3N nanosheets for efficient full water splitting catalysis

2017 ◽  
Vol 5 (19) ◽  
pp. 9377-9390 ◽  
Author(s):  
Tingting Liu ◽  
Mian Li ◽  
Chuanlai Jiao ◽  
Mehboob Hassan ◽  
Xiangjie Bo ◽  
...  
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
Cell Voltage ◽  
Electrolysis Cell ◽  
Design And Synthesis ◽  
A Cell ◽  
Carbon Microfibers ◽  
A Current

A (−) Ni3N/CMFs/Ni3N‖Ni3N/CMFs/Ni3N (+) electrolysis cell requires a cell voltage of only 1.65 V to achieve a current density of 20 mA cm−2.

scholarly journals Ni2P nanocrystals embedded Ni-MOF nanosheets supported on nickel foam as bifunctional electrocatalyst for urea electrolysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haitao Wang ◽  
Haiyan Zou ◽  
Yingying Liu ◽  
Zhenglong Liu ◽  
Wenshuang Sun ◽  
...  
Keyword(s):  
Oxidation Reaction ◽  
Nickel Foam ◽  
Metal Organic Framework ◽  
Cell Voltage ◽  
Bifunctional Electrocatalyst ◽  
Electrochemical Application ◽  
Urea Electrolysis ◽  
Metal Organic ◽  
A Cell ◽  
A Current

AbstractIt’s highly desired but challenging to synthesize self-supporting nanohybrid made of conductive nanoparticles with metal organic framework (MOF) materials for the application in the electrochemical field. In this work, we report the preparation of Ni2P embedded Ni-MOF nanosheets supported on nickel foam through partial phosphidation (Ni2P@Ni-MOF/NF). The self-supporting Ni2P@Ni-MOF/NF was directly tested as electrode for urea electrolysis. When served as anode for urea oxidation reaction (UOR), it only demands 1.41 V (vs RHE) to deliver a current of 100 mA cm−2. And the overpotential of Ni2P@Ni-MOF/NF to reach 10 mA cm−2 for hydrogen evolution reaction HER was only 66 mV, remarkably lower than Ni2P/NF (133 mV). The exceptional electrochemical performance was attributed to the unique structure of Ni2P@Ni-MOF and the well exposed surface of Ni2P. Furthermore, the Ni2P@Ni-MOF/NF demonstrated outstanding longevity for both HER and UOR. The electrolyzer constructed with Ni2P@Ni-MOF/NF as bifunctional electrode can attain a current density of 100 mA cm−2 at a cell voltage as low as 1.65 V. Our work provides new insights for prepare MOF based nanohydrid for electrochemical application.

scholarly journals A Cellulose Electrolysis Cell with Metal-Free Carbon Electrodes

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 106 ◽  
Author(s):  
Yaorong Li ◽  
Masahiro Nagao ◽  
Kazuyo Kobayashi ◽  
Yongcheng Jin ◽  
Takashi Hibino
Keyword(s):  
Hydrogen Production ◽  
Raw Materials ◽  
Water Electrolysis ◽  
Mesoporous Structure ◽  
Carbon Anode ◽  
Electrolysis Cell ◽  
Cathode Reaction ◽  
Production Of Hydrogen ◽  
Onset Voltage ◽  
A Current

Biomass raw materials, including agricultural residues, collected weeds, and wood chips, are important feedstocks for hydrogen production. Numerous attempts have been made to electrolyze biomass directly or indirectly to hydrogen because these processes allow for the production of hydrogen with less power consumption than water electrolysis. However, expensive metal-based electrocatalysts are needed, especially for the cathode reaction, in the electrolysis cells. Results from the present study demonstrate the production of hydrogen directly from cellulose, using an optimal mesoporous carbon as the cathode in addition to a partially oxygenated carbon anode at a temperature of 150 °C, with an electrolysis onset voltage of ca. 0.2 V, a current density of 0.29 A cm−2 at an electrolysis voltage of 1 V, and a current efficiency of approximately 100% for hydrogen production. These characteristics were comparable to those recorded when using a Pt/C anode and cathode under the same conditions. The sp2 planes of the carbon allowed π electrons to be donated to protons at the cathode. In addition, the mesoporous structure provided a sufficient amount of sp2 planes on the surface of the cathode.

Porous and amorphous cobalt hydroxysulfide core–shell nanoneedles on Ti-mesh as a bifunctional electrocatalyst for energy-efficient hydrogen production via urea electrolysis

2021 ◽  
Author(s):  
Yu Jiang ◽  
Shanshan Gao ◽  
Gongchen Xu ◽  
Xiaoming Song
Keyword(s):  
Hydrogen Production ◽  
High Activity ◽  
Energy Efficient ◽  
Bifunctional Catalyst ◽  
Core Shell ◽  
Bifunctional Electrocatalyst ◽  
Urea Electrolysis ◽  
Ti Mesh

Porous and amorphous CoSx(OH)y core–shell nanoneedles covered by numerous ultra-thin small nanosheets are synthesized successfully on Ti-mesh, and act as a high activity and stability bifunctional catalyst for urea electrolysis.

scholarly journals Water Electrolysis Using a Porous IrO2/Ti/IrO2 Catalyst Electrode and Nafion Membranes at Elevated Temperatures

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 330
Author(s):  
Je-Deok Kim ◽  
Akihiro Ohira
Keyword(s):  
Elevated Temperatures ◽  
High Current Density ◽  
Water Electrolysis ◽  
Gas Diffusion ◽  
Membrane Electrode ◽  
Porous Ti ◽  
Diffusion Layers ◽  
Iro2 Catalyst ◽  
Ti Powder ◽  
Catalyst Electrode

Porous IrO2/Ti/IrO2 catalyst electrodes were obtained by coating IrO2 on both sides of three types of porous Ti powder sheets (sample 1, sample 2, and sample 3) using different surface treatment methods, and a hydrogen evolution catalyst electrode was obtained by coating Pt/C on carbon gas diffusion layers. A Nafion115 membrane was used as an electrolyte for the membrane electrode assemblies (MEA). Water electrolysis was investigated at cell temperatures up to 150 °C, and the electrical characteristics of the three types of porous IrO2/Ti/IrO2 catalyst electrodes were investigated. The sheet resistance of sample 1 was higher than those of samples 2 and 3, although during water electrolysis, a high current density was observed due to the nanostructure of the IrO2 catalyst. In addition, the structural stabilities of Nafion and Aquivion membranes up to 150 °C were investigated by using small angle X-ray scattering (SAXS). The polymer structures of Nafion and Aquivion membranes were stable up to 80 °C, whereas the crystalline domains grew significantly above 120 °C. In other words, the initial polymer structure did not recover after the sample was heated above the glass transition temperature.

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