Papers by Diego Cazorla-amorós
The template carbonization technique enables the production of porous carbons and carbon-based co... more The template carbonization technique enables the production of porous carbons and carbon-based composites with precisely designed, controlled pore structures. The resulting templated carbons are therefore useful to investigate and understand the relation between carbon nanostructure and electrocapacitive properties. In this short review paper, we introduce our works on electrochemical capacitance using zeolite-templated carbons and carbon-coated anodic aluminum oxide.La técnica de nanomoldeo mediante carbonización de plantillas sólidas infiltradas permite la preparación y el diseño de materiales carbonosos porosos, tanto puros como compuestos, donde las estructuras porosas son fácilmente definibles y controlables. Los carbones nanomoldeados resultantes son muy útiles como materiales modelo para estudiar las relaciones entre la nanostructura del carbón y sus propiedades electrocapacitivas. En este trabajo, realizamos una breve revisión de nuestros estudios sobre la capacidad electroq...
Pd-Core-Based Core–Shell Nanoparticles for Catalytic and Electrocatalytic Applications
Keys and New Trends of Iron-Based Catalysts in Selective Oxidation of Propylene in Gas Phase
Chemosphere, 2021
h i g h l i g h t s g r a p h i c a l a b s t r a c t Electrochemical regeneration of spent ACs w... more h i g h l i g h t s g r a p h i c a l a b s t r a c t Electrochemical regeneration of spent ACs was studied at different reactor scales. A recovery of the surface area of 96% was achieved after 8 h of treatment. In the 3.5 kg electrochemical cell, a 95% of the AC surface area was recovered. Electrochemistry can provide a green and in-situ alternative to regenerate spent AC.
Nanomaterials, 2019
Biographene was successfully produced in water from graphite flakes by a simple, rapid, and effic... more Biographene was successfully produced in water from graphite flakes by a simple, rapid, and efficient methodology based on a bioexfoliation technology. The methodology consisted in the application of a lipase, with a unique mechanism of interaction with hydrophobic surfaces, combined with a previous mechanical sonication, to selectively generate lipase-graphene sheets conjugates in water at room temperature. The adsorption of the lipase on the graphene sheets permits to keep the sheets separated in comparison with other methods. It was possible to obtain more than 80% of graphene (in the form of multi-layer graphene) from low-cost graphite and with less damage compared to commercial graphene oxide (GO) or reduced GO. Experimental analysis demonstrated the formation of multi-layer graphene (MLG) mainly using lipase from Thermomyces Lanuginosus (TLL).
Langmuir, 2017
In this work, the influence of the interaction between the iron and cobalt-phthalocyanines (FePc ... more In this work, the influence of the interaction between the iron and cobalt-phthalocyanines (FePc and CoPc) and carbon nanotubes (CNTs) used as support in the electroactivity towards oxygen reduction reaction (ORR) in alkaline media has been investigated. A series of thermal treatments were performed on these materials in order to modify the interaction between the CNTs and the phtalocyanines. The FePc-based catalysts showed the highest activity, with comparable performance to the state-of-the-art Pt-Vulcan catalyst. A heat treatment at 400 ºC improved the activity of FePc-based catalysts, while the use of higher temperatures or oxidative atmosphere rendered to the decomposition of the macrocyclic compound and consequently the loss of the electrochemical activity of the complex. CoPc-based catalysts performance was negatively affected for all the tested treatments. Thermogravimetric analyses demonstrated that the FePc was stabilized when loaded onto CNTs, while CoPc did not show such feature, pointing to a better interaction of the FePc instead of the CoPc. Interestingly, electrochemical measurements demonstrated an improvement of the electron transfer rate in thermally treated FePc-based catalysts. They also allowed us to assess that only 15% of the iron in the catalyst was available for direct electron transfer. This is the same iron amount that remains on the catalyst after a strong acid washing with concentrated HCl (ca. 0.3 wt.%), which is enough to deliver a comparable ORR activity. Durability tests confirmed that the catalysts deactivation occurs at slower rate in those catalysts where FePc is strongly attached to the CNT surface. Thus, the highest ORR activity seems to be provided by those FePc
Electrochimica Acta, 2007
Polyaniline/porous carbon composite electrodes were prepared by chemical polymerization and chara... more Polyaniline/porous carbon composite electrodes were prepared by chemical polymerization and characterized in terms of porosity and performance as electrochemical capacitors To obtain the composite electrodes two methods were used. The first method consisted of mixing, directly, the activated carbon with chemically polymerized polyaniline. The second one consisted of mixing the activated carbon with aniline and subsequent chemical polymerization. Additionally, the second process was carried out with the porous carbon previously thermally treated in N 2 up to 900ºC in order to remove surface oxygen groups. Changes in porosity with the polyaniline addition were analysed. It has been proved that the method used strongly affects the porous structure. Dealing with the electrochemical performance, polyaniline and carbon mechanically mixed seem to work independently, being the composite behaviour a combination of the corresponding performance of both materials separately. The composites prepared by the second method (polymerization over carbon) reveal the key role of surface chemistry in polyaniline coating. Aniline reacts with the oxygen complexes and their positive effect in capacitance is not observed. The second method (polymerization over carbon) using a thermally treated carbon seems to be the best one since a more porous (or thinner) polyaniline film is produced.
Catalysis Today, 2001
In this paper, a study on the hydrogenation of carvone by using Pt
Carbon, 2014
In situ Raman spectroscopy was exploited to analyze the interaction between carbon and hydrogen d... more In situ Raman spectroscopy was exploited to analyze the interaction between carbon and hydrogen during electrochemical hydrogen storage at cathodic conditions. Two different activated carbons were used and characterized by different electrochemical techniques in two electrolytes (6 M KOH and 0.5 M Na 2 SO 4). The in situ Raman spectra collected showed that, in addition to the D and G bands associated to the graphitic carbons, two bands appear simultaneously at about 1110 and 1500 cm À1 under cathodic conditions, and then they disappear when the potential increases to more positive values. This indicates that carbon-hydrogen bonds are formed reversibly in both electrolytes during cathodic conditions. Comparing the two activated carbons, it was confirmed that, in both electrolytes, the hydrogenation of carbon atoms is produced more easily for the sample with lower amount of surface oxygen groups. In KOH medium, for the two samples, the formation of carbon-hydrogen bonds proceeds at more positive potential with respect to the thermodynamic potential value for hydrogen evolution. Furthermore, changes in the shape of the D band (due to an intensity increase of the D1 band) during the formation of carbon-hydrogen bonds suggest that hydrogenation of the carbon atoms increases the number of edge planes.
The effects of hydrogen on thermal desorption of oxygen surface complexes
Carbon, 1997
Temperature programmed desorption/reduction techniques have been applied to an investigation of t... more Temperature programmed desorption/reduction techniques have been applied to an investigation of the interaction of hydrogen with oxygen surface complexes and reactive sites on the surface of a resin char during thermal desorption. It is shown that the presence of hydrogen has a number of significant effects on the evolution patterns of the oxides of carbon and water vapor. A number
Electrochimica Acta, 2013
Any queries or remarks that have arisen during the processing of your manuscript are listed below... more Any queries or remarks that have arisen during the processing of your manuscript are listed below and highlighted by flags in the proof. Click on the 'Q' link to go to the location in the proof. Location in Query / Remark: click on the Q link to go article Please insert your reply or correction at the corresponding line in the proof Q1 Please confirm that given names and surnames have been identified correctly. Q2 The name of the author in Ref. [25] is different from that mentioned in the text. Please check, and correct if necessary. Q3 Please note that Refs. [17,53] and [20,54] were identical, and Refs. [53,54] have been deleted. The subsequent references have been renumbered. Q4 As per the reference style of this journal, all journal references must contain article title. Please check and provide the same. Please check this box if you have no corrections to make to the PDF file Thank you for your assistance. Please cite this article in press as: D. Salinas-Torres, et al., Asymmetric hybrid capacitors based on activated carbon and activated carbon fibre-PANI electrodes, Electrochim. Acta (2012),
Preparación de fibras de carbón (FC) a partir de breas de petróleo: Estudio de la estabilización con yodo
Electrochimica Acta, 2021
The electrochemical performance of nitrogen-doped and non-doped superporous activated carbons as ... more The electrochemical performance of nitrogen-doped and non-doped superporous activated carbons as electrodes for supercapacitors was assessed in organic and ionic liquid-based electrolytes. The nitrogen functionalization was carried out through post-modification treatments at mild conditions to produce N-doped activated carbons that preserve the microporosity of the pristine carbon material. The electrodes based on these materials provide large capacitance values (up to 150-180 F/g) in both 1M Pyr14TFSI/PC and 1M Pyr14BF4/PC due to their tailored porous texture, given by their well-developed microporosity and low mesopore volume. The electrochemical double layer capacitors based on these materials displayed outstanding capacitance (37-40 F/g and 14 F/cm 3 ) and energy values (44-48 Wh/kg and 16-17 Wh/L). The nitrogen-doped activated carbons evidence high stability at positive and negative polarization potentials due the presence of specific N functionalities. The results prove that surface chemistry of carbon materials plays a key role on their degradation under high operation voltage conditions. The durability of the devices can be improved by doping carbon electrodes with selected nitrogen groups, such as nitrogen heterocycles and amine-like surface functionalities.
On the Pathways of N-Doped Carbon Materials Active Sites During Oxygen Reduction Reaction
SSRN Electronic Journal, 2021
N-doped carbon materials have been considered as one of the most promising options for the replac... more N-doped carbon materials have been considered as one of the most promising options for the replacement of platinum-based electrocatalysts towards the oxygen reduction reaction. However, what is known about this kind of catalysts and the identification of the active sites is still contradictory. Most of the scientific literature focuses on experimental characterization before ORR testing, leading to a consistent lack of knowledge about the surface chemistry at operando conditions. The development of operando techniques is, up to now, not enough to unravel with accuracy the reasons why these catalysts are as active as platinum-based electrodes and to understand the deactivation with time of use. In this work, the changes occurring in the active sites of N-doped carbon catalysts have been analysed in detail through pre- and post-ORR extended characterization of selectively N-doped carbon materials, along with sophisticated computational modelling.
Corrigendum to “Multi‐wall carbon nanotubes electrochemically modified with phosphorus and nitrogen functionalities as a basis for bioelectrodes with improved performance” [Electrochimica Acta 387 (2021) 138530]
Electrochimica Acta, 2021
Catálisis de la gasificación del carbón por calcio: mecanismos de reacción
En esta Tesis se ha profundizado en el estudio del Calcio como catalizador en los procesos de gas... more En esta Tesis se ha profundizado en el estudio del Calcio como catalizador en los procesos de gasificacion del carbon, desde un punto de vista fundamental. Se ha analizado su comportamiento desde la misma etapa de preparacion hasta su funcionamiento durante la reaccion. De este modo se han cubierto los siguientes puntos fundamentales: 1) Distribucion del calcio durante la introduccion; efecto de la quimica superficial del carbon en el contacto calcio-carbon. 2) Analisis de la reaccion CO2-CaO en CaO masico con el fin de conocer con profundidad este sistema para su posterior aplicacion en el sistema calcio-carbon. 3) Estudio de la interaccion calcio-carbon con el fin de interpretar la actividad catalitica y conocer el mecanismo de reaccion y fase activa. 4) Comportamiento del catalizador en condiciones de reaccion.
About the exclusive mesoporous character of MCM-41
Studies in Surface Science and Catalysis, 2002
Abstract Physical gas adsorption was used to study the porous texture of two silicas prepared in ... more Abstract Physical gas adsorption was used to study the porous texture of two silicas prepared in this work. These two silicas are the ordered mesoporous material named MCM-41, and a precipitated silica that was prepared under identical conditions but without the use of a templating agent as in the case of MCM-41. Physical gas adsorption of N 2 at 77 K (covering the relative pressure range of 10 6 to 1) and CO 2 at 273 K (subatmospheric and high pressures, covering the relative fugacity range of 10 5-0.7) were carried out on the ...
Adsorption on activated carbon fibers
Adsorption by Carbons, 2008
Activated carbon fibers (ACFs) are porous carbons with a fiber shape and a well-defined porous st... more Activated carbon fibers (ACFs) are porous carbons with a fiber shape and a well-defined porous structure that can be prepared with a high adsorption capacity. Although the ACFs are very promising materials, they have not still a market as important as the activated carbons (ACs) due to their difference in production costs. The main characteristics and advantages of the ACFs are as follows 1. ; 2. ; 3. .
Electrophoretic Deposition for the Synthesis of Inorganic Membranes
Membranes for Membrane Reactors: Preparation, Optimization and Selection, 2011
In situ methods used to characterize calcium as a catalyst of carbon gasification reactions
Catalysis Today, 1991
... situ". ITPD Surface heterogeneity has been confirmed by an intermittent temperature-... more ... situ". ITPD Surface heterogeneity has been confirmed by an intermittent temperature-programmed desorption method (ITPD) with the same apparatus (and reactor) as that used for experiments reported above (ref. 3). The ITPD ...
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Papers by Diego Cazorla-amorós