First International Conference on
Unconventional Catalysis, Reactors and Applications

Zaragoza-Spain, 16-18 October 2019
11:40   Unconventional catalyst synthesis and manufacturing methods 7
Chair: Jordi Llorca
11:40
20 mins

#78
GAS-PHASE GROWN CARBON NANOSTRUCTURES AS COSMIC DUST ANALOGUES
jose angel martin-gago, Lidia Martinez, gonzalo Santoro, Pablo Merino, mario acolla (presenter: Jose Angel Martin-Gago)
Abstract: Cosmic dust is formed in the circumstellar environments of dying stars. In these particular regions of the universe, the accretion from the gaseous phase produces small clusters and nanoparticles which are then ejected to the interstellar medium where energetic processing takes place. Fabrication and processing of nanoparticles in the laboratory, at conditions resembling those at the atmosphere of dying stars, constitutes and invaluable tool to understand the chemical complexity in space. Thus, we have designed and built a novel ultra-high vacuum machine to simulate in the laboratory the formation of cosmic dust [1]. We have fabricated carbon nanoparticles and nanostructures in the gas phase from carbon atoms and molecular hydrogen using magnetron aggregation sources. Starting form C atoms and molecular hydrogen we have been able to grow C-nanoparticles of about 7 nm of diameter and molecules and clusters. In particular depending on the Hydrogen density, we grow alkanes and polyethylene fibers, or small C-clusters with a low degree of hydrogenation. Our results suggest that the observed aromatic species in space are not efficiently formed in the circumstellar environments of dying stars but after the processing of the carbon clusters on the surface of cosmic dust grains [2].
12:00
20 mins

#79
LIGAND-FREE ATOMIC QUANTUM CLUSTERS SYNTHESIZED BY SOFT CHEMICAL METHODS: OUTSTANDING CATALYTIC PROPERTIES
M. Arturo Lopez Quinela, Buceta David, Blanca Dominguez, Nerea Borja (presenter: Nerea Borja)
Abstract: LIGAND-FREE ATOMIC QUANTUM CLUSTERS SYNTHESIZED BY SOFT CHEMICAL METHODS: OUTSTANDING CATALYTIC PROPERTIES M. Arturo López-Quintela, David Buceta, Blanca Domínguez, Iria Rodríguez, Nerea Borja Nanomag Group, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain maloplez.quintela@usc.es Keywords: Clusters, Catalysts Atomic Quantum Clusters (AQCs) are formed by a small number of atoms (< ≈ 150) and represent a new family of compounds with novel and fascinating properties, which strongly differ from both, bulk and nanoparticles of the same material. For example, fluorescent, magnetic, catalytic, etc. properties have been found in AQCs1, which are not exhibited for the same material in larger sizes. In the last years soft chemical methods have been developed to synthesize AQCs without using protecting or capping ligands2, which may hinder their properties. This offers now the possibility to explore their properties in detail. In this talk it will be firstly summarized the state-of-the art of the kinetic-control synthesis methods, explaining in detail the mechanisms involved in such methods3. To show the precise control on the size of AQCs, which can be achieved with these methods, we will explain the synthesis of monodisperse samples of Cu5-AQCs and Ag3-AQCs. Secondly, we will focus on some important applications of clusters in catalysis, highlighting the particular consequences in biomedicine4. References 1. See e.g. B. S. González and M. A. López-Quintela, Functional Nanometer-Sized Clusters of Transition Metals: Synthesis,Properties and Applications, The Royal Society of Chemistry, 2014, pp. 25–50; S. M. Copp, A. Gorovits, S. M. Swasey, S. Gudibandi, P. Bogdanov and E. G. Gwinn, ACS Nano, 2018, 12, 8240–8247; M. A. Abbas, P. V. Kamat and J. H. Bang, ACS Energy Lett. 2018, 3, 840–854; L. Liu and A. Corma, Chem. Rev., 2018, 118, 4981–5079. 2. S. Huseyinova, J. Blanco, F. G. Requejo, J. M. Ramallo-López, M. C. Blanco, D. Buceta and M. A. López-Quintela, J. Phys. Chem. C, 2016, 120, 15902–15908; D. Buceta, N. Busto, G. Barone, J. M. Leal, F. Domínguez, L. J. Giovanetti, F. G. Requejo, B. García, M. A. López-Quintela, Angew. Chem., Int. Ed. 2015, 54, 7612. 3. Y. Piñeiro, D. Buceta, J. Calvo, S. Huseyinova, M. Cuerva, A. Pérez, B. Domínguez, M.A. López-Quintela, J. Colloid Interface Sci. 2015, 449, 279−285. 4. V. Porto et al. Adv. Mater., 2018, 30, 1801317.
12:20
20 mins

#68
MICROWAVE FLOW SYNTHESIS OF TIO2 NANOTUBES
Yingjian Luo, Ana Serrano, King Lun Yeung, Miguel Ángel Bañares (presenter: Ana Serrano-Lotina)
Abstract: TiO2 nanotubes (TNTs) are versatile materials that have multiple applications: biomedicine, photocatalysis, photo-splitting of water or dye sensitized solar cells among others. They can be prepared via anodization, sol–gel, hydrothermal and vapour deposition techniques1. Microwave-assisted synthesis possesses exclusive benefits of uniform, rapid, and volumetric heating and is able to significantly reduce the preparation time2. Microwave flow synthesis can add new profits such as shorter times or milder conditions. The aim of this work is to study the influence of different parameters (T, p or contact time) in the TNTs preparation by microwave flow synthesis. Different catalysts were prepared using anatase TiO2 and NaOH as reactants and with the following conditions: T = 85-130 ºC, p = 2-4 bar, t = 15-30 min. All the samples were characterized by XRD, Raman spectroscopy and TEM in order to determine if TNTs where obtained. TNTs were obtained when p = 4 bar and T was 120 ºC.
12:40
20 mins

#73
ENHANCEMENT OF THE CATALYTIC ACTIVITY OF PALLADIUM NANOPARTICLES OBTAINED BY A GREEN SYNTHESIS IN A MICROFLUIDIC DEVICE
Esteban G. Gioria, Francisco P. Wisniewski, Laura B. Gutierrez (presenter: Laura Gutierrez)
Abstract: Synthesis of palladium nanoparticles (PdNPs) employing glucose and starch as green reagents was performed using two different reaction configurations: (i) the conventional batch method (PdNPs-B) and (ii) the continuous microreactor technology (PdNPs-M). The synthetized nanoparticles were characterized by UV-vis spectroscopy and TEM. The reaction conducted in the microreactor led to smaller PdNPs with a monodispersed size distribution. The catalytic response of both obtained materials was tested on a reduction of 4-nitrophenol. As a result, the smaller PdNPs synthesized with the continuous flow presented higher catalytic activity than the bigger ones synthesized with the batch configuration, proving the high catalytic surface area of small nanoparticles.