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

Abstract

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.

Materials-Related Aspects of Thermochemical Water and Carbon Dioxide Splitting: A Review

“…Kodama tested coated foam devices consisting of magnesium oxide (MgO)-partially stabilized Zirconia (MPSZ) which were coated with Fe 3 O 4 /YSZ or NiFe 2 O 4 /ZrO 2 particles [69,76]. Thirty-two cycles were performed with a Fe 3 O 4 /YSZ/MPSZ foam device at a thermal reduction temperature of 1673–1723 K and a water-splitting temperature of 1373 K. The foam device was broken after 32 cycles [77].…”

“…The reactor was tested with a MPSZ foam coated with NiFe 2 O 4 /ZrO 2 (described in Chapter 2.2.1). Hydrogen was produced in six cycles, but large temperature gradients were observed in the foam [ 76 ]. A solar demonstration with a 5 kW th dish concentrator with a coated MPSZ foam is planned to be tested at Inha University, Korea [ 68 ].…”

Theoretical Material Research with First Principle Calculation Aiming at High-efficiency Hydrogen Production Using Solar Thermochemical Energy

“…In the two-step thermal redox reaction, various metal oxides have been used as catalytic reaction ceramics to improve hydrogen gas production e ciency. Hercynite (FeAl 2 O 4 ) was used by Ehrhart and his colleagues at the beginning of the hydrogen gas production study 23 [32][33] . Among these experiments, the research on cerium oxide has been promoted in recent years [34][35][36][37] .…”