scholarly journals Development of Synthesis and Fabrication Process for Mn-CeO2 Foam via Two-Step Water-Splitting Cycle Hydrogen Production

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6919
Author(s):  
Hyun-Seok Cho ◽  
Tatsuya Kodama ◽  
Nobuyuki Gokon ◽  
Selvan Bellan ◽  
Jong-Kyu Kim
Keyword(s):  
Hydrogen Production ◽  
Water Splitting ◽  
Spin Coating ◽  
Weight Percent ◽  
Thermal Reduction ◽  
Coprecipitation Method ◽  
Ceramic Foam ◽  
Synthesis Methods ◽  
Reactive Metal ◽  
New Synthesis

The effects of doping manganese ions into a cerium oxide lattice for a thermochemical two-step water-splitting cycle to produce oxygen and hydrogen and new synthesis methods were experimentally investigated. In order to comparison of oxygen/hydrogen producing performance, pristine CeO2, a coprecipitation method for Mn-CeO2, and a direct depositing method for Mn-CeO2 with different particle sizes (50~75, 100–212, over 212 μm) and doping extents (0, 5, 15 mol%) were tested in the context of synthesis and fabrication processes of reactive metal oxide coated ceramic foam devices. Sample powders were coated onto zirconia (magnesium partially stabilized zirconia oxide, MPSZ) porous foam at 30 weight percent using spin coating or a direct depositing method, tested using a solar reactor at 1400 °C as a thermal reduction step and at 1200 °C as a water decomposition step for five repeated cycles. The sample foam devices were irradiated using a 3-kWth sun-simulator, and all reactive foam devices recorded successful oxygen/hydrogen production using the two-step water-splitting cycles. Among the seven sample devices, the 5 mol% Mn-CeO2 foam device, that synthesized using the coprecipitation method, showed the greatest hydrogen production. The newly suggested direct depositing method, with its contemporaneous synthesis and coating of the Mn-CeO2 foam device, showed successful oxygen/hydrogen production with a reduction in the manufacturing time and reactants, which was lossless compared to conventional spin coating processes. However, proposed direct depositing method still needs further investigation to improve its stability and long-term device durability.

Ferrite-Loaded Ceramic Foam Devices Prepared by Spin-Coating Method for a Solar Two-Step Thermochemical Cycle

2009 ◽  
Author(s):  
Nobuyuki Gokon ◽  
Tatsuya Kodama ◽  
Ayumi Nagasaki ◽  
Ko-ichi Sakai ◽  
Tsuyoshi Hatamachi
Keyword(s):  
Water Splitting ◽  
Spin Coating ◽  
Thermal Reduction ◽  
Input Power ◽  
Ceramic Foam ◽  
High Porosity ◽  
Thermochemical Cycle ◽  
Spin Coating Method ◽  
Coating Method ◽  
Reactor Operating

A two-step water-splitting thermochemical cycle using redox working material of iron-based oxide (ferrite) particles has been developed for converting solar energy into hydrogen. The two-step thermochemical cycle for producing a solar hydrogen from water requires a development of a high temperature solar-specific receiver-reactor operating at 1000–1500°C. In the present work, ferrite-loaded ceramic foams with a high porosity (7 cells per linear inch) were prepared as a water splitting device by applying ferrite/zirconia particles on a MgO-partially stabilized Zirconia (MPSZ) ceramic foam. The water splitting foam device was prepared using a new method of spin coating. A spin coating method we newly employed that has advantages of shortening preparation period and reducing of the coating process in comparison to previous preparation method reported. The water-splitting foam devices, thus prepared, were examined on hydrogen productivity and reactivity through a two-step thermochemical cycle. NiFe2O4/m-ZrO2/MPSZ and Fe3O4/c-YSZ/MPSZ foam devices were firstly tested for thermal reduction of ferrite using the laboratory scale receiver-reactor by a sun-simulator to simulate concentrated solar radiation. Subsequently, with another quartz reactor the light-irradiated device was reacted with steam by infrared furnace. As a result, it was possible to perform cyclic reactions over several times and to produce hydrogen through thermal-reduction at 1500°C and water-decomposition at 1100–1200°C. In further experiments, the NiFe2O4/m-ZrO2/MPSZ foam device was successfully demonstrated in a windowed single reactor for cyclic hydrogen production by solar-simulated Xebeam irradiation with input power of 1 kW. The NiFe2O4/m-ZrO2/MPSZ foam device produced hydrogen of 70–190μmol per gram of device through 6 cycles and reached ferrite conversion of 60% at a maximum.

A Reactive Fe-YSZ Coated Foam Device for Solar Two-Step Water Splitting

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Tatsuya Kodama ◽  
Tomoki Hasegawa ◽  
Ayumi Nagasaki ◽  
Nobuyuki Gokon
Keyword(s):  
Flux Density ◽  
Water Splitting ◽  
Redox System ◽  
Power Input ◽  
Thermal Reduction ◽  
Inert Atmosphere ◽  
Ceramic Foam ◽  
Total Power ◽  
Stabilized Zirconia ◽  
High Temperature Reaction

A thermochemical two-step water-splitting cycle using a redox system of iron-based oxides or ferrites is one of the promising processes for converting solar energy into clean hydrogen in sunbelt regions. An iron-containing yttrium-stabilized zirconia (YSZ) or Fe-YSZ is a promising working redox material for the two-step water-splitting cycle. Fe2+-YSZ is formed by a high-temperature reaction between YSZ and Fe3O4 supported on the YSZ at 1400°C in an inert atmosphere. Fe2+-YSZ reacts with steam and generates hydrogen at 1000–1100°C to form Fe3+-YSZ that is reactivated by thermal reduction in a separate step at temperatures above 1400°C under an inert atmosphere. In the present study, ceramic foam coated with Fe-YSZ particles is examined as the thermochemical water-splitting device to be used in a solar directly irradiated receiver/reactor system. The Fe-YSZ particles were coated on an Mg-partially stabilized zirconia foam disk, and the foam device was tested during the two-step water-splitting cycle; this was performed alternately at temperatures between 1100°C and 1400°C. The foam device was irradiated by concentrated visible light from a sun simulator at a peak flux density of 925 kW/m2 and an average flux density of 415 kW/m2 (total power input on the surface of the foam was 0.296 kW) in a N2 gas stream; subsequently, it was reacted with steam at 1100°C while heating by an infrared furnace. Hydrogen successfully continued to be produced in the repeated cycles.

Thermodynamic Analysis of Mixed-Metal Ferrites for Hydrogen Production by Two-Step Water Splitting

Solar Energy ◽  
2006 ◽  
Author(s):  
Mark D. Allendorf ◽  
Richard B. Diver ◽  
James E. Miller ◽  
Nathan P. Siegel
Keyword(s):  
Hydrogen Production ◽  
Metal Oxides ◽  
Water Splitting ◽  
Thermodynamic Analysis ◽  
Thermal Reduction ◽  
Spinel Ferrites ◽  
Mixed Metal ◽  
Production Of Hydrogen ◽  
Splitting Process

A thermodynamic analysis of the two-step water splitting process for the production of hydrogen is reported in this paper. Calculations simulating the preparation of ferrite samples, their thermal reduction to form a mixture of metal oxides, and subsequent reoxidation with steam to produce hydrogen were performed. Mixed-metal spinel ferrites of the general form MFe2O4, where M = Co, Ni, or Zn, are compared with iron spinel, Fe3O4. The results indicate that of the four ferrites examined, nickel spinel has the most favorable combination of properties for use in two-step water splitting.

Reactive Fe-YSZ Coated Foam Devices for Solar Two-Step Water Splitting

2007 ◽  
Author(s):  
Tatsuya Kodama ◽  
Tomoki Hasegawa ◽  
Ayumi Nagasaki ◽  
Nobuyuki Gokon
Keyword(s):  
Flux Density ◽  
Water Splitting ◽  
Redox System ◽  
Thermal Reduction ◽  
Inert Atmosphere ◽  
Ceramic Foam ◽  
Stabilized Zirconia ◽  
High Temperature Reaction ◽  
Separate Step ◽  
Average Flux

A thermochemical two-step water splitting cycle using a redox system of iron-based oxides or ferrites is one of the promising processes for converting solar energy into clean hydrogen in sunbelt regions. An iron-containing YSZ (Yttrium-Stabilized Zirconia) or Fe-YSZ is a promising working redox material for the two-step water splitting cycle. The Fe2+ YSZ is formed by a high-temperature reaction between YSZ, and Fe3O4 supported on the YSZ at 1400°C in an inert atmosphere. The Fe2+-YSZ reacts with steam and generate hydrogen at 1000–1100°C, to form Fe3+-YSZ that is re-activated by a thermal reduction in a separate step at temperatures above 1400°C under an inert atmosphere. In the present work, a ceramic foam coated with the Fe-YSZ particles is examined as the thermochemical water splitting device for use in a solardirectly-irradiated receiver/reactor system. The Fe-YSZ particles were coated on an Mg-partially-stabilized zirconia foam disk and the foam device was tested on the two-step water splitting cycle being performed alternately at temperatures between 1100 and 1400°C. The foam device was irradiated by concentrated visible light from a sun-simulator at the peak flux density of 1000 kW/m2 and the average flux density of 470 kW/m2 in a N2 gas stream, and then, was reacted with steam at 1100°C while heating by an infrared furnace. Hydrogen successfully continued to be produced in the repeated cycles.

scholarly journals Experimental study of Mn-CeO2 coated ceramic foam device for two-step water splitting cycle hydrogen production with 3kW sun-simulator

2020 ◽  
Author(s):  
Hyun-Seok Cho ◽  
Tatsuya Kodama ◽  
Nobuyuki Gokon ◽  
Selvan Bellan ◽  
Naoyoshi Nishigata
Keyword(s):  
Experimental Study ◽  
Hydrogen Production ◽  
Water Splitting ◽  
Ceramic Foam

Thermochemical two-step water-splitting for hydrogen production using Fe-YSZ particles and a ceramic foam device

Energy ◽  
2008 ◽  
Vol 33 (9) ◽  
pp. 1407-1416 ◽  
Author(s):  
Nobuyuki Gokon ◽  
Tomoki Hasegawa ◽  
Shingo Takahashi ◽  
Tatsuya Kodama
Keyword(s):  
Hydrogen Production ◽  
Water Splitting ◽  
Ceramic Foam

Hydrogen Production by Solar Thermochemical Water-Splitting/Methane-Reforming Process

Solar Energy ◽  
2003 ◽  
Author(s):  
Tatsuya Kodama ◽  
Yoshiyasu Kondoh ◽  
Atsushi Kiyama ◽  
Ken-Ich Shimizu
Keyword(s):  
Hydrogen Production ◽  
Metal Oxide ◽  
Water Splitting ◽  
Thermal Energy ◽  
Experimental Studies ◽  
Reduction Process ◽  
Thermal Reduction ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
Solar Thermochemical

Two different routes of solar thermochemical hydrogen production are reviewed. One is two-step water splitting cycle by using a metal-oxide redox pair. The first step is based on the thermal reduction of metal oxide, which is a highly endothermic process driven by concentrated solar thermal energy. The second step involves water decomposition with the thermally-reduced metal oxide. The first thermal reduction process requires very-high temperatures, which may be realized in sun-belt regions. Another hydrogen production route is solar reforming of natural gas (methane), which can convert methane to hydrogen via calorie-upgrading by using concentrated solar thermal energy. Solar reforming is currently the most advanced solar thermochemical process in sun belt. There is also possibility for the solar reforming to be applied for worldwide solar concentrating facilities where direct insolation is weaker than that in sun belt. Our experimental studies to improve the relevant catalytic technologies are shown and discussed.

Semiconductor Photocatalysts for Solar-to-Hydrogen Energy Conversion: Recent Advances of CdS

2020 ◽  
Vol 16 ◽  
Author(s):  
Yuxue Wei ◽  
Honglin Qin ◽  
Jinxin Deng ◽  
Xiaomeng Cheng ◽  
Mengdie Cai ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Visible Light ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Visible Light Irradiation ◽  
Noble Metals ◽  
Light Irradiation ◽  
Photocatalytic Hydrogen Evolution ◽  
Theoretical Design ◽  
Recent Developments

Introduction: Solar-driven photocatalytic hydrogen production from water splitting is one of the most promising solutions to satisfy the increasing demands of a rapidly developing society. CdS has emerged as a representative semiconductor photocatalyst due to its suitable band gap and band position. However, the poor stability and rapid charge recombination of CdS restrict its application for hydrogen production. The strategy of using a cocatalyst is typically recognized as an effective approach for improving the activity, stability, and selectivity of photocatalysts. In this review, recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation are summarized. In particular, the factors affecting the photocatalytic performance and new cocatalyst design, as well as the general classification of cocatalysts, are discussed, which includes a single cocatalyst containing noble-metal cocatalysts, non-noble metals, metal-complex cocatalysts, metal-free cocatalysts, and multi-cocatalysts. Finally, future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are described. Background: Photocatalytic hydrogen evolution from water splitting using photocatalyst semiconductors is one of the most promising solutions to satisfy the increasing demands of a rapidly developing society. CdS has emerged as a representative semiconductor photocatalyst due to its suitable band gap and band position. However, the poor stability and rapid charge recombination of CdS restrict its application for hydrogen production. The strategy of using a cocatalyst is typically recognized as an effective approach for improving the activity, stability, and selectivity of photocatalysts. Methods: This review summarizes the recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation. Results: Recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation are summarized. The factors affecting the photocatalytic performance and new cocatalyst design, as well as the general classification of cocatalysts, are discussed, which includes a single cocatalyst containing noble-metal cocatalysts, non-noble metals, metal-complex cocatalysts, metal-free cocatalysts, and multi-cocatalysts. Finally, future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are described. Conclusion: The state-of-the-art CdS for producing hydrogen from photocatalytic water splitting under visible light is discussed. The future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are also described.

A Strategy for Preparing High-efficiency and Economical Catalytic Electrodes toward Overall Water Splitting

Nanoscale ◽  
2021 ◽  
Author(s):  
Dongxue Yao ◽  
Lingling Gu ◽  
Bin Zuo ◽  
Shuo Weng ◽  
Shengwei Deng ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Water Splitting ◽  
Production Technology ◽  
High Purity ◽  
High Efficiency ◽  
Energy Development ◽  
Overall Water Splitting ◽  
Important Field ◽  
High Purity Hydrogen

The technology of electrolyzing water to prepare high-purity hydrogen is an important field in today's energy development. However, how to prepare efficient, stable, and inexpensive hydrogen production technology from electrolyzed...

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