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Álvarez-Manuel L, Alegre C, Sebastián D, Napal PF, Lázaro MJ. Tailored Porous Carbon Xerogels for Fe-N-C Catalysts in Proton Exchange Membrane Fuel Cells. Nanomaterials (Basel) 2023; 14:14. [PMID: 38202469 PMCID: PMC10780504 DOI: 10.3390/nano14010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/07/2023] [Accepted: 12/14/2023] [Indexed: 01/12/2024]
Abstract
Atomically dispersed Fe-N-C catalysts for the oxygen reduction reaction (ORR) have been synthesized with a template-free method using carbon xerogels (CXG) as a porous matrix. The porosity of the CXGs is easily tunable through slight variations in the synthesis procedure. In this work, CXGs are prepared by formaldehyde and resorcinol polymerization, modifying the pH during the process. Materials with a broad range of porous structures are obtained: from non-porous to micro-/meso-/macroporous materials. The porous properties of CXG have a direct effect on Fe-N-CXG activity against ORR in an acidic medium (0.5 M H2SO4). Macropores and wide mesopores are vital to favor the mass transport of reagents to the active sites available in the micropores, while narrower mesopores can generate additional tortuosity. The role of microporosity is investigated by comparing two Fe-N-C catalysts using the same CXG as the matrix but following a different Fe and N doping procedure. In one case, the carbonization of CXG occurs rapidly and simultaneously with Fe and N doping, whereas in the other case it proceeds slowly, under controlled conditions and before the doping process, resulting in the formation of more micropores and active sites and achieving higher activity in a three-electrode cell and a better durability during fuel cell measurements. This work proves the feasibility of the template-free method using CXG as a carbon matrix for Fe-N-C catalysts, with the novelty of the controlled porous properties of the carbon material and its effect on the catalytic activity of the Fe-N-C catalyst. Moreover, the results obtained highlight the importance of the carbon matrix's porous structure in influencing the activity of Fe-N-C catalysts against ORR.
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Affiliation(s)
| | - Cinthia Alegre
- Instituto de Carboquímica, Consejo Superior de Investigaciones Científicas, 50018 Zaragoza, Spain; (L.Á.-M.); (D.S.); (P.F.N.)
| | | | | | - María Jesús Lázaro
- Instituto de Carboquímica, Consejo Superior de Investigaciones Científicas, 50018 Zaragoza, Spain; (L.Á.-M.); (D.S.); (P.F.N.)
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Cebollada J, Sebastián D, Lázaro MJ, Martínez-Huerta MV. Carbonized Polydopamine-Based Nanocomposites: The Effect of Transition Metals on the Oxygen Electrocatalytic Activity. Nanomaterials (Basel) 2023; 13:nano13091549. [PMID: 37177094 PMCID: PMC10180844 DOI: 10.3390/nano13091549] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023]
Abstract
The electrochemical oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the most critical processes in renewable energy-related technologies, such as fuel cells, water electrolyzers, and unitized regenerative fuel cells. N-doped carbon composites have been demonstrated to be promising ORR/OER catalyst candidates because of their excellent electrical properties, tunable pore structure, and environmental compatibility. In this study, we prepared porous N-doped carbon nanocomposites (NC) by combining mussel-inspired polydopamine (PDA) chemistry and transition metals using a solvothermal carbonization strategy. The complexation between dopamine catechol groups and transition metal ions (Fe, Ni, Co, Zn, Mn, Cu, and Ti) results in hybrid structures with embedded metal nanoparticles converted to metal-NC composites after the carbonization process. The influence of the transition metals on the structural, morphological, and electrochemical properties was analyzed in detail. Among them, Cu, Co, Mn, and Fe N-doped carbon nanocomposites exhibit efficient catalytic activity and excellent stability toward ORR. This method improves the homogeneous distribution of the catalytically active sites. The metal nanoparticles in reduced (MnO, Fe3C) or metallic (Cu, Co) oxidation states are protected by the N-doped carbon layers, thus further enhancing the ORR performance of the composites. Still, only Co nanocomposite is also effective toward OER with a potential bifunctional gap (ΔE) of 0.867 V. The formation of Co-N active sites during the carbonization process, and the strong coupling between Co nanoparticles and the N-doped carbon layer could promote the formation of defects and the interfacial electron transfer between the catalyst surface, and the reaction intermediates, increasing the bifunctional ORR/OER performance.
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Affiliation(s)
- Jesús Cebollada
- Instituto de Catálisis y Petroleoquímica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid, Spain
| | - David Sebastián
- Instituto de Carboquímica, CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - María Jesús Lázaro
- Instituto de Carboquímica, CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
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Gebreslase GA, Sebastián D, Martínez-Huerta MV, Tsoncheva T, Tsyntsarski B, Georgiev G, Lázaro MJ. CoFe-loaded P, N co-doped carbon foam derived from petroleum pitch waste: an efficient electrocatalyst for oxygen evolution reaction. Catal Today 2022. [DOI: 10.1016/j.cattod.2022.12.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Gebreslase GA, Sebastián D, Martínez-Huerta MV, Lázaro MJ. Nitrogen-doped carbon decorated-Ni3Fe@Fe3O4 electrocatalyst with enhanced oxygen evolution reaction performance. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gebreslase GA, Martínez-Huerta MV, Sebastián D, Lázaro MJ. NiCoP/CoP sponge-like structure grown on stainless steel mesh as a high-performance electrocatalyst for hydrogen evolution reaction. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Gebreslase GA, Martínez-Huerta MV, Sebastián D, Lázaro MJ. Transformation of CoFe 2O 4 spinel structure into active and robust CoFe alloy/N-doped carbon electrocatalyst for oxygen evolution reaction. J Colloid Interface Sci 2022; 625:70-82. [PMID: 35714410 DOI: 10.1016/j.jcis.2022.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/24/2022] [Accepted: 06/02/2022] [Indexed: 12/26/2022]
Abstract
Electrochemical water splitting is an environmentally benign technology employed for H2 production; however, it is critically hampered by the sluggish kinetics of the oxygen evolution reaction (OER) at the positive electrode. In this work, nitrogen-doped carbon-coated CoFe electrocatalysts were synthesized via a three-step route comprising (1) hydrothermal reaction, (2) in-situ polymerization of dopamine and (3) carbonization. The effect of carbonized polydopamine on the overall physicochemical properties and electrochemical activity of CoFe catalysts was systematically studied. By controlling and optimizing the ratio of CoFe2O4 and dopamine contents, a transformation of the CoFe2O4 structure to CoFe alloy was observed. It was found that CoFe/NC30% (prepared with 30% dopamine) exhibits an excellent catalytic activity towards OER. A small overpotential of 340 mV was required to generate a current density of 10 mA cm-2 in a 1.0 M KOH electrolyte. More importantly, the CoFe/NC30% catalyst reflected exceptional durability for at least 24 h. This research sheds light on the development of affordable, highly efficient, and durable electrocatalysts for OER.
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Affiliation(s)
| | | | - David Sebastián
- Instituto de Carboquímica, CSIC. Miguel Luesma, Castán 4, 50018 Zaragoza, Spain
| | - María Jesús Lázaro
- Instituto de Carboquímica, CSIC. Miguel Luesma, Castán 4, 50018 Zaragoza, Spain.
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Luque-Centeno JM, Martínez-Huerta MV, Sebastián D, Pérez-Rodríguez S, Lázaro MJ. Titanium Dioxide/N-Doped Graphene Composites as Non-Noble Bifunctional Oxygen Electrocatalysts. Ind Eng Chem Res 2021; 60:18817-18830. [PMID: 35645458 PMCID: PMC9134212 DOI: 10.1021/acs.iecr.1c02896] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 11/29/2022]
Abstract
Bifunctional oxygen electrocatalysts are essential in the development of low-temperature unitized regenerative fuel cells (URFCs), as a promising alternative for storing energy via hydrogen. TiO2, as a semiconductor material, is commonly not established as an active electrocatalyst for oxygen reduction and oxygen evolution due to its poor electrical conductivity and low reactivity. Here, we demonstrated that composites composed of TiO2 and N-doped graphene can be active in oxygen reduction and evolution reactions in an alkaline environment. Combination factors such anatase/rutile interaction, N-doping graphene, and the presence of Ti3+/Ti-N species raise the active sites and improve the electrochemical activity. Our results may afford an opportunity to develop a non-noble and promising electrocatalyst in energy storage technology.
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Affiliation(s)
- José Manuel Luque-Centeno
- Instituto de Catálisis y Petroleoquímica (CSIC), Marie Curie 2, 28049, Madrid, Spain.,Instituto de Carboquímica (CSIC), Miguel Luesma Castán 4, 50018, Zaragoza, Spain
| | | | - David Sebastián
- Instituto de Carboquímica (CSIC), Miguel Luesma Castán 4, 50018, Zaragoza, Spain
| | - Sara Pérez-Rodríguez
- Instituto de Carboquímica (CSIC), Miguel Luesma Castán 4, 50018, Zaragoza, Spain
| | - María Jesús Lázaro
- Instituto de Carboquímica (CSIC), Miguel Luesma Castán 4, 50018, Zaragoza, Spain
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Pérez-Rodríguez S, Sebastián D, Alegre C, Tsoncheva T, Petrov N, Paneva D, Lázaro MJ. Biomass waste-derived nitrogen and iron co-doped nanoporous carbons as electrocatalysts for the oxygen reduction reaction. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.138490] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Torres D, Pérez-Rodríguez S, Sebastián D, Pinilla JL, Lázaro MJ, Suelves I. Capacitance Enhancement of Hydrothermally Reduced Graphene Oxide Nanofibers. Nanomaterials (Basel) 2020; 10:E1056. [PMID: 32486258 PMCID: PMC7352485 DOI: 10.3390/nano10061056] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/07/2020] [Accepted: 05/09/2020] [Indexed: 11/16/2022]
Abstract
Nanocarbon materials present sp2-carbon domains skilled for electrochemical energy conversion or storage applications. In this work, we investigate graphene oxide nanofibers (GONFs) as a recent interesting carbon material class. This material combines the filamentous morphology of the starting carbon nanofibers (CNFs) and the interlayer spacing of graphene oxide, and exhibits a domain arrangement accessible for fast transport of electrons and ions. Reduced GONFs (RGONFs) present the partial removal of basal functional groups, resulting in higher mesoporosity, turbostratic stacking, and surface chemistry less restrictive for transport phenomena. Besides, the filament morphology minimizes the severe layer restacking shown in the reduction of conventional graphene oxide sheets. The influence of the reduction temperature (140-220 °C) on the electrochemical behaviour in aqueous 0.5 M H2SO4 of RGONFs is reported. RGONFs present an improved capacitance up to 16 times higher than GONFs, ascribed to the unique structure of RGONFs containing accessible turbostratic domains and restored electronic conductivity. Hydrothermal reduction at 140 °C results in the highest capacitance as evidenced by cyclic voltammetry and electrochemical impedance spectroscopy measurements (up to 137 F·g-1). Higher temperatures lead to the removal of sulphur groups and slightly thicker graphite domains, and consequently a decrease of the capacitance.
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Affiliation(s)
- Daniel Torres
- Instituto de Carboquímica, Consejo Superior de Investigaciones Científicas (CSIC), Miguel Luesma Castán 4, 50018 Zaragoza, Spain; (S.P.-R.); (D.S.); (J.L.P.); (M.J.L.); (I.S.)
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Rizo R, Lázaro MJ, Pastor E, García G. Spectroelectrochemical Study of Carbon Monoxide and Ethanol Oxidation on Pt/C, PtSn(3:1)/C and PtSn(1:1)/C Catalysts. Molecules 2016; 21:molecules21091225. [PMID: 27626404 PMCID: PMC6273622 DOI: 10.3390/molecules21091225] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 08/30/2016] [Accepted: 09/07/2016] [Indexed: 02/04/2023] Open
Abstract
PtSn-based catalysts are one of the most active materials toward that contribute ethanol oxidation reaction (EOR). In order to gain a better understanding of the Sn influence on the carbon monoxide (principal catalyst poison) and ethanol oxidation reactions in acidic media, a systematic spectroelectrochemical study was carried out. With this end, carbon-supported PtSnx (x = 0, 1/3 and 1) materials were synthesized and employed as anodic catalysts for both reactions. In situ Fourier transform infrared spectroscopy (FTIRS) and differential electrochemical mass spectrometry (DEMS) indicate that Sn diminishes the amount of bridge bonded CO (COB) and greatly improves the CO tolerance of Pt-based catalysts. Regarding the effect of Sn loading on the EOR, it enhances the catalytic activity and decreases the onset potential. FTIRS and DEMS analysis indicate that the C-C bond scission occurs at low overpotentials and at the same potential values regardless of the Sn loading, although the amount of C-C bond breaking decreases with the rise of Sn in the catalytic material. Therefore, the elevated catalytic activity toward the EOR at PtSn-based electrodes is mainly associated with the improved CO tolerance and the incomplete oxidation of ethanol to form acetic acid and acetaldehyde species, causing the formation of a higher amount of both C2 products with the rise of Sn loading.
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Affiliation(s)
- Rubén Rizo
- Departamento de Química, Instituto de Materiales y Nanotecnología, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, La Laguna 38071, Santa Cruz de Tenerife, Spain.
| | - María Jesús Lázaro
- Instituto de Carboquímica (CSIC) Miguel Luesma Castan 4, Zaragoza 50018, Spain.
| | - Elena Pastor
- Departamento de Química, Instituto de Materiales y Nanotecnología, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, La Laguna 38071, Santa Cruz de Tenerife, Spain.
| | - Gonzalo García
- Departamento de Química, Instituto de Materiales y Nanotecnología, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, La Laguna 38071, Santa Cruz de Tenerife, Spain.
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Alegre C, Gálvez ME, Moliner R, Baglio V, Stassi A, Aricò AS, Lázaro MJ. Platinum Ruthenium Catalysts Supported on Carbon Xerogel for Methanol Electro-Oxidation: Influence of the Catalyst Synthesis Method. ChemCatChem 2013. [DOI: 10.1002/cctc.201300542] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Álvarez G, Alcaide F, Miguel O, Calvillo L, Lázaro MJ, Quintana JJ, Calderón JC, Pastor E. Technical electrodes catalyzed with PtRu on mesoporous ordered carbons for liquid direct methanol fuel cells. J Solid State Electrochem 2009. [DOI: 10.1007/s10008-009-0913-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Echegoyen Y, Suelves I, Lázaro MJ, Moliner R, Palacios JM, Müller JO, Su D, Schlögl R. Characterization of carbon nanofibers grown over Ni and Ni-cu catalysts. J Nanosci Nanotechnol 2009; 9:4170-4179. [PMID: 19916425 DOI: 10.1166/jnn.2009.m27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Carbon nanofibers were obtained by thermo-catalytic decomposition of methane at 700 degrees C over Ni and Ni-Cu catalysts prepared by different methods (co-precipitation, impregnation and fusion) and using either Al or Mg as textural promoter. Characterization of the carbon thus obtained was performed by N2 adsorption isotherms (BET surface area), temperature programmed desorption (TPD), temperature programmed oxidation (TPO), X-ray diffraction, Raman spectrometry, and electron microscopy SEM and TEM. The carbon obtained possesses high crystallinity and poor surface chemistry. The crystallinity is enhanced when using Mg as textural promoter and in the presence of copper. SEM and TEM examinations show that the fibers have fishbone structure and they grow generally from one nickel particle (tip growing) although there are some bidirectional growing. Copper-doping lead to the formation of thicker filaments and promotes the formation of bamboo-like structures. Catalyst particles higher than 100 nm do not promote the formation of nanofibers and the carbon deposits as uniform coatings.
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Affiliation(s)
- Y Echegoyen
- Instituto de Carboquímica CSIC, Miguel Luesma Castán, 4. 50015-Zaragoza, Spain
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Lázaro MJ, Sebastián D, Suelves I, Moliner R. Carbon nanofiber growth optimization for their use as electrocatalyst support in proton exchange membrane (PEM) fuel cells. J Nanosci Nanotechnol 2009; 9:4353-4359. [PMID: 19916456 DOI: 10.1166/jnn.2009.m59] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Carbon nanofiber (CNF) growth by catalytic decomposition of methane in a fixed-bed reactor was studied out to elucidate the influence of some important reaction conditions: temperature, space velocity and reactant partial pressure, in the morphological properties of the carbonaceous material obtained. The main objective is to synthesize a suitable carbonaceous nanomaterial to be used as support in platinum based electrocatalysts for Proton Exchange Membrane Fuel Cells (PEMFC) which improves current carbon blacks. High specific surface area is required in an electrocatalyst support since platinum dispersion is enhanced and so a cost-effective usage and high catalytic activity. Good electrical conductivity of carbon support is also required since the fuel cell power density is improved. With this proposal, characterization was carried out by nitrogen physisorption, XRD, SEM and TPO. The results were analysed by a factorial design and analysis of variance (ANOVA) in order to find an empirical correlation between operating conditions and CNF characteristics. It was found that the highest specific surface area and pore volume were found at 823 K and at a space velocity of 10 L gcat(-1) h(-1). The graphitic character of CNF, which is known to influence the electrical conductivity, presented a maximum value at temperatures between 923 K and 973 K. SEM images showed a narrow size distribution of CNF diameter between 40 and 90 nm and homogeneous appearance.
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Affiliation(s)
- M J Lázaro
- Instituto de Carboquímica CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
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Calvillo L, Lázaro MJ, Suelves I, Echegoyen Y, Bordejé EG, Moliner R. Study of the surface chemistry of modified carbon nanofibers by oxidation treatments in liquid phase. J Nanosci Nanotechnol 2009; 9:4164-4169. [PMID: 19916424 DOI: 10.1166/jnn.2009.m26] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Carbon nanofibers (CNF) were grown by thermocatalytic decomposition of methane. Their texture and surface chemistry were modified by different oxidation treatments with HNO3 at different concentrations or a mixture of HNO3-H2SO4 to optimise their ability of dispersing active metal particles, because this material will be used as electrocatalytic support for polymeric electrolyte fuel cells. The effect of liquid phase oxidation on the surface chemistry and the textural properties of the CNF was studied by temperature programmed desorption (TPD), scanning electron microscopy (SEM) and N2-physisorption. Moreover, their thermal stability was studied by temperature programmed oxidation (TPO). During oxidation treatments functional groups were created and their number was function of the oxidation treatment conditions. Results indicated that an increase in severity of the oxidation treatment produces an increase in the number of surface oxygen groups and in the thermal stability. However, a very severe treatment can destroy partially the structure of carbon nanofibers.
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Affiliation(s)
- L Calvillo
- Instituto de Carboquímica (CSIC), Miguel Luesma Castán 4, 50018 Zaragoza, Spain
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Alcaide F, Álvarez G, Miguel O, Lázaro MJ, Moliner R, López-Cudero A, Solla-Gullón J, Herrero E, Aldaz A. Pt supported on carbon nanofibers as electrocatalyst for low temperature polymer electrolyte membrane fuel cells. Electrochem commun 2009. [DOI: 10.1016/j.elecom.2009.03.023] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Salgado JRC, Quintana JJ, Calvillo L, Lázaro MJ, Cabot PL, Esparbé I, Pastor E. Carbon monoxide and methanol oxidation at platinum catalysts supported on ordered mesoporous carbon: the influence of functionalization of the support. Phys Chem Chem Phys 2008; 10:6796-806. [PMID: 19015783 DOI: 10.1039/b809227c] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The influence of different functionalization treatments of the support on the electrocatalytic activity towards CO and methanol oxidation at platinum nanoparticles deposited on ordered mesoporous carbons (OMC) has been studied for the first time. Before deposition of the metal, the carbon support was functionalized applying several procedures, with the purpose to generate oxygenated groups for anchoring the Pt nanoparticles by the formic acid (FM) and borohydride (BM) reduction methods. Good dispersion of the catalyst was obtained in all cases. It has been shown that particle size, and consequently the lattice parameter and metal surface area, depends on the functionalization treatment employed. CO and methanol electrooxidation was studied at all prepared catalysts applying cyclic voltammetry. It was observed that CO stripping occurs at more negative potentials (around 0.10-0.15 V) with these supports with respect to Vulcan XC-72 supported catalysts, and the best results for both methods were achieved with OMC functionalized with concentrated nitric acid for 0.5 h. This carbon support presents a higher amount of oxygenated groups without the loss of the ordered structure. In situ infrared studies have been performed for the first time with this type of catalyst, showing that the effect of the carbon support on the CO oxidation potential is similar to the presence of a second metal as Ru under the same experimental conditions. Methanol electrooxidation is also dependent on the nature of the support, as proved from both cyclic voltammetry and chronoamperometry. In this case, results depend on the method of nanoparticles preparation and seem to be better for BM.
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Affiliation(s)
- J R C Salgado
- Departamento de Química Física, Universidad de la Laguna, Avda. Astrofísico Francisco Sánchez, 38071, La Laguna, Santa Cruz de Tenerife, Spain
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