Síntesis de cerámicas conductoras de protón por Flame Spray Pyrolysis

Author

Soriano Hernández, Iván Gaspar                                                   

Abstract

Currently, several industrial sectors need real-time monitoring of hydrogen or its isotopes, such as occurs in high-temperature processes in the metallurgical industry or in future nuclear fusion technology. In response to the lack of commercial devices capable of on-site measurements given adverse operating conditions, prototypes of hydrogen sensors based on solid-state electrolytes have emerged. These materials have certain crystalline structures that have ionic conductivity, such as the perovskite type ceramic Sr(Ce0,9Zr0,1)0,95Yb0,05O3-δ, selected for the development of this Master's Thesis due to its promising properties related to the conductivity of the proton. With this, a study begins on the influence of the initial particle size of this ceramic on the manufacture and properties of a hydrogen sensor. In order to reach the nanoscale in the synthesis of ceramic particles, a tubular reactor heated by electrical resistance was simulated with SolidWorks software. The final design obtained from the simulations resulted to be inconvenient due to technical factors related to its construction and operation, so the system was discarded. As an alternative, a Flame Spray Pyrolysis system was developed. All the components of this system were purchased. Gas, combustion and drainage control systems tested. Future work is required to finish the particle extraction and filtering system, as well as experimentation with the flame synthesis process.
The ceramic Sr(Ce0,9Zr0,1)0,95Yb0,05O3-δ was synthesized by the citrate method. The product powder was characterized by XRD, SEM microscopy and laser diffraction, concluding that the ceramic powder was made up of particles of several sizes, 1.46μm (27%), 12.39μm (41%) and 200.01μm (32 %). Subsequently, a ceramic tablet- haped piece was formed and sintered. After its characterization, it was used to build a H2 sensor with which amperometric measurements were carried out at 500ºC and 600ºC, applying 2V and 4V. The influence of these parameters on the sensor response was verified and sensitivity values were obtained. The same ceramic was synthesized using the glycine method. After characterizing the powder obtained with positive results, it could be verified that this technique allows obtaining a majority particle size of 18.10 μm (67% of the total). Lastly, a ceramic piece was formed, sintered and characterized.

Director

Colominas Fuster, Sergi
Abellà Iglesias, Jordi

Degree

IQS SM - Master’s Degree in Chemical Engineering

Date

2020-07-15