The control of the microstructure, through micro- and/or nano-engineering, is crucial in several relevant industrial processes, biomaterials and energy related fields, such as: design and fabrication of potential support material for biofiltration, production of biofuels, design and performance enhancement of Solid Oxide Fuel Cell materials, ceramic bone replacement, improvement of photoelectrodes for Solar Cells, TiO2-based catalyst for the wastewaters treatments, separation membranes stable at high temperatures, nanomaterials for hydrogen storage applications, improved catalysts for heterogeneous catalysis, microstructural design of exhaust catalyst materials, Li-batteries, etc. Hence, we are exploring new approaches for such control.
Engineering of materials for Solid Oxide Fuel Cells and other energy and environmental applications. J.C. Ruiz-Morales, D. Marrero-López, M. Gálvez-Sánchez, J. Canales-Vázquez, C. Savaniu and S.N. Savvin
Energy and Environmental Science 2010, vol.3(11), p.1670-1681. link
New SOFC anode materials
Design of new SOFC anode materials with enhaced catalytic properties towards the direct oxidation of hydrocarbons. These staudies are mainly focused in the system (La,Sr)(Ti,M)O3 (M=Ga,Mn,Sc,Fe,Nb). The origin of this work is the Jesús Canales-Vázquez's PhD thesis (awarded with the best PhD Thesis in 2004 in Solid State Chemistry, School of Chemistry, St. Andrews, Scotland, UK).
Disruption of extended defects in solid oxide fuel cell anodes for methane oxidation. J. C. Ruiz-Morales, Jesús Canales-Vázquez, Cristian Savaniu, David Marrero-López, Wuzong Zhou and John T. S. Irvine.
Nature 2006, vol.439, p.568-571. link
Symmetric Solid Oxide Fuel Cells
In 2006 an alternative approach to the traditional SOFC configuration was proposed. In this configuration the same material is simultaneously used as both anode and cathode, as in the polymeric electrolyte membrane fuel cells. Symmetryc solid oxide fuel cells present several advantages compared to conventional SOFCs, because the number of cell components are reduced facilitating the assembly of a fuel cell in a single thermal treatment and minimising compatibility requirements. Furthermore, this configuration could overcome two of the main drawbacks associated to SOFC technology when operating directly with hydrocarbon fuels, i.e. reversible sulphur poisoning and carbon deposition, due to the possibility -despite the engineering issue- to reverse the gas flow oxidising any sulphur specie or C-deposit and hence recovering any loss of performance.
Symmetric and Reversible Solid Oxide Fuel Cells. J. C. Ruiz-Morales, D. Marrero-López, J. Canales-Vázquez & John T.S. Irvine.
RSC Advances 2011, vol.1(8), p.1403-1414. link
On the simultaneous use of La0.75Sr0.25Cr0.5Mn0.5O3-δ as both anode and cathode material with improved microstructure in Solid Oxide Fuel Cells. J. C. Ruiz-Morales, J. Canales-Vázquez, J. Peña-Martínez, D. Marrero-López & P. Núnez.
Electrochim. Acta 2006, vol.52(1), p.278-284. link
A novel design, alternative to the conventional electrolyte-supported Solid Oxide Fuel Cell is presented. In this new design, a honeycomb-electrolyte is fabricated from hexagonal cells, providing high mechanical strength to the whole structure and supporting the thin layer used as electrolyte of a SOFC. This new design allows a reduction of ~70% of the electrolyte material and it renders high volumetric power densities, i.e. 1.22 W/cm3 under pure CH4 at 900ºC.
Performance of a novel type of electrolyte-supported solid oxide fuel cell with honeycomb structure. J.C. Ruiz-Morales, D. Marrero-López, J. Peña-Martínez, J. Canales-Vázquez, J. J. Roa, M. Segarra, S.N. Savvin & P.Nunez.
J. Power Sources 2010, vol.195, p.516-521. link
3D printing for SOFC assembly
We are testing the possibility to control de microstructure of materials using the light comming from a common Powerpoint proyector and a UV-sensible material. This allow the creation of any type of 3D complex structure, layer by layer, in few seconds. The combination with YSZ and glassy carbon microspheres has been also tested with good resolution down to the 100 microns and, 40 microns as the lowest thickness layer using a 300$ projector.
Prospective use of the 3D printing technology for the microstructural engineering of Solid Oxide Fuel Cell components. E. Hernández, P. Acosta-Mora, J. Méndez-Ramos, E. Borges, P. Esparza, J. Canales-Vázquez, P. Núñez & J. C. Ruiz-Morales.
Bol. Soc. Esp. Ceram. V, 2014, vol.53(5), 213-216. link
Support materials for biofilms
YSZ-based honeycomb biofilters were fabricated and tested with several organic volatile compounds (VOCs) such as toluene, xylene and ethylbenzene, rendering performances of 80% in the removal of these contaminants. Hence YSZ can be recovered from a SOFC that have reached the end of its lifetime and then a biofilter can be fabricated and used for VOCs removal with high efficiencies. Compared to traditional plastic filter, the YSZ-based filters can be regenerated after firing in oxidising conditions at 600 ºC for few hours.
Fabrication of YSZ-based Honeycomb Biofilters. Gorka Gallastegui, Ana Elías and Juan Carlos Ruiz-Morales.
Int. J. Applied Ceram. Technology, 2011, vol.8(6), 1305-1311, link
Design of TiO2-based photocatalyts
One of the most promising materials for removing organic pollutants, because of its photocatalytic activity, is the anatase-type TiO2. This activity can be enhanced through modification of the microstructure of TiO2 or any other material used as a porous support.
Collaboration/testing Dr. Pedro Esparza, Inorganic Dpt., ULL.
TiO2 modifications by hydrothermal treatment and doping to improve its photocatalytic behaviour under visible light. P. Esparza, T. Hernández, M. E. Borges, M. C. Álvarez-Galván, J. C. Ruiz-Morales and J.L.G. Fierro. .
Catalysis Today, 2013, vol (210), 135-141, link
Improved catalyst for biofuel production
Biodiesel can be produced from ecological friendly processes, new or used processing plant oil, waste oil or animal fats. The production of biodiesel involves a chemical reaction between an oil or animal fat and methanol to create a mixture of methyl esters and glycerol. In order to reduce the energy needed for the reaction to proceed, a basic catalyst is added. And the structure of this catalyst, specially at nanometer scale, can boost the efficiency of the biofuels production.
Collaboration/testing Dr. Emma Borges, Chemical Engineering Dpt., ULL.
Improvement of Biodiesel Production Through Microstructural Engineering of a Heterogeneous Catalyst. M. E. Borges, Juan Carlos Ruiz-Morales and L. Díaz.
Journal of Industrial and Engineering Chemistry, 2012, vol(19), 791-796, link