Continuous hydrothermal flow synthesis of Gd‐doped CeO₂ (GDC) nanoparticles for inkjet printing of SOFC electrolytes

Abstract

Gd x Ce 1-x O 2-d (GDC) nanoparticles were synthesized, using continuous hydrothermal flow synthesis. By varying the synthesis conditions, particle size and morphology could be tailored. Here, particle sizes between 6 and 40 nm with polyhedral or octahedral shape could be obtained. Gd 0.2 Ce 0.8 O 2-d nanoparticles were further processed into inks for inkjet printing. Despite the small particle size/large surface area, inks with excellent printing behavior were formulated. For proof-of-concept, thin GDC layers were printed on a) green NiO-GDC substrates, and on b) presintered NiO-YSZ substrates. While no dense layers could be obtained on the green NiO-GDC substrates, GDC nanoparticles printed on NiO-YSZ substrates formed a dense continuous layer after firing at 1300°C.

Solvothermal Synthesis Routes to Substituted Cerium Dioxide Materials

“…Slostowski et al produced La-and Pr-substituted ceria in a custom-built, continuous flow reactor in supercritical water, up to 400 • C, and formed crystallites less than 10 nm in size, observing that higher temperature allowed a higher level of element substitution [147]. Xu et al used supercritical water at 396 • C and rapid mixing,~29 s, with solutions of metal salts and KOH to yield Gd-CeO 2 [148]. Their apparatus, Figure 18, had a further two stages of heating points before allowing the product to be tapped as a slurry.…”

Promotion of oxygen reduction and evolution by applying a nanoengineered hybrid catalyst on cobalt free electrodes for solid oxide cells

“…The process details can be found elsewhere. 26 Shortly, in an inhouse developed CHFS flow-type reactor, a precursor stream of Ce(NO3)3 (0.04 mol L -1 ) and Gd(NO3)3 (0.01 mol L -1 ) was mixed with a stream of supercritical water (396 °C, 26 MPa). The nanocrystals nucleated and grew upon mixing.…”

“…1a shows that CGO nanocrystals have well-defined octahedral shapes with sizes between 25-45 nm and mainly expose (111) facets with the lattice fringes at 0.31 nm. 26,34 Shown in Fig. 1b is a typical SEM image of the bare LSF electrode backbone after firing at 1100°C for 5 h, showing smooth surfaces and clear grains.…”

Chemistry in supercritical fluids for the synthesis of metal nanomaterials

“…85 Secondly, high controllability of particle characteristics can be achieved by tuning process parameters such as temperature, pressure, residence time and nature of reactants in the absence of in situ functionalization agents during the supercritical fluid synthesis. 115,130,131 Given that, in addition to the in situ functionalization, it is also possible to separate the particle synthesis process from the surface functionalization step, named ex situ functionalization, providing a rather flexible selection of functionalization agents applied right after the synthesis of crude particles for various purposes. 81,86,132 For instance, by directly spraying the roomtemperature outflow containing crude Pd NPs from the decomposition of palladium bis(trifluoroacetate) in supercritical acetone to the solutions of functionalization agents (e.g.…”