On April 11, 2023, researchers from the Czech Academy of Sciences and the Onoma University of Madrid published a study titled 3Dprinting of Cubic Zirconia Lattice Supports for Hydrogenproduction in Ceramics International** In this paper, we report the preparation of highly porous 3D mode robotic casting 8YSZ scaffolds and immersion them in palladium nanocatalysts, and preliminarily study their catalytic performance in FA hydrogen production. After mechanical casting, the 8YSZ scaffold underwent rheological characterization and sintered at different temperatures to find the right balance between the high porosity required to immobilize the PD nanoparticles on the ceramic filaments after the impregnation step with sufficient compressive strength, and to support the harsh conditions of catalytic fixed-bed reactors.
Original link:
About the study
A catalytic method for the production of hydrogen is described, using a lightweight, highly porous 3D mode 8mol% yttrium-stabilized cubic zirconia scaffold for machine casting, heat treatment, and impregnation of palladium (PD) catalytic nanoparticles, followed by a fixed-bed reactor for catalytic dehydrogenation of renewable formic acid (FA). With this method, CO-free H is continuously generated, and the Fa conversion rate is 32%.
Fig. 1a) Apparent viscosity ( ) vs. shear rate ( ) of 8ySZ ink;b) The relationship between shear storage (g) and loss (g) modulus and shear stress ( ).
Fig. 2a) A set of 8ySZ brackets that have been heat-treated at different temperatures. The illustrations correspond to the CAD model. b) Optical image of the 8YSZ-1200 holder showing the open channel and filaments of the patterned structure. Fesem micrograph of the break 3D8YSZ-1200 showing the printed stack (C), detail of a rod (D). Fesem images of the surface microstructure of 1000 (E) and 1400 (F) sintered rods.
Fig. 3a) The stress-strain curve is a representative example;b) The ratio of the average compressive strength ( ) to the total porosity ( ) of sintered 8ysz scaffolds at different temperatures (1000 1400).
Figure 4 in 1200 and 1400 arrhenius representations of the ionic conductivity of sintered scaffolds and dense pellets. a) The apparent total conductivity ( ) is determined by the external dimensions of the structure;b) Considering the conductive area of the contact rod passing through the three-dimensional structure, the bracket is corrected.
Figure 5A) Comparison of the 3D 8YSZ-1200 scaffold (left) with a fresh 3DPD 8YSZ catalyst (right), B) Palladium nucleus-level XPS spectra of a fresh 3DPD 8YSZ catalyst, and C) TEM microscopy of some palladium nanoparticles on the surface of the 8YSZ particles of a fresh 3DPD 8YSZ catalyst**.
Fig. 6 studies the catalytic performance of the three-dimensional PD 8YSZ catalyst for continuous hydrogen production by FA decomposition. Fa conversion rate (x) and gas flow rate (q) as a function of in-flow time, using the following operating conditions: CFA, 0 = 1 m, QL = 025 ml min,wcat= 4 g, t = 55℃，p= 1 atm。
Figure 7: Percentage of H molar and H Co molar ratio of gas produced by the Fa decomposition reaction catalyzed by the three-dimensional PD 8YSZ catalyst.
Conclusions of the study
The experimental results show that the frameless cylindrical cell 8YSZ scaffold fabricated by mechanical casting using pseudoplastic water-based ink has a yield stress of 380Pa. By sintering the printed pattern structures at different temperatures (1000-1400 °C), lightweight 3D ceramic scaffolds can be developed. The total porosity of these scaffolds can be regulated between 88% and 75%, rod porosity from 61% to 14%, and 8ysz grain sizes from 20 nm to 2 m. Depending on the application requirements, the compressive strength can be in the range of 06 to 69MPa between controls. At a sintering temperature of 1400 °C, the 8YSZ scaffold exhibits the properties of an ionic conductor, and its conductivity is about 800 °C and 5 S m, which is suitable for the application of electrolyte membrane.
At the sintering temperature of 1200, the highly porous 3D printing structure was uniformly coated with PD nanoparticles to form a 3dpd 8ysz catalyst. The catalyst can be used in the catalytic dehydrogenation of renewable FA to continuously produce Co-free H. In a fixed-bed reactor, the FA conversion rate of PD and PD reached 32%. This is the first time that a 3D catalyst-based structural reactor has been applied to this type of dehydrogenation.
END——The ceramic 3D printer independently developed and sold by QIYU Technology can print the structure of zirconia filter element, providing a one-stop system solution covering "3D printing materials + printing equipment + debinding and sintering process", and has cooperated with hundreds of scientific research institutes, welcome to inquire.
QIYU Technology 3D printed zirconia filter element structure.