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Pyrenetetraone-based covalent organic framework as an effective electrocatalyst for oxygen reduction reaction

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Nano Research 2022年第5期15卷 3907-3912页

作者： Paloma Garcia-Arroyo Emiliano Martinez-Perinan Jorge J.Cabrera-Trujillo Elena Salagre Enrique G.Michel Jose I.Martinez Encarnacion Lorenzo Jose L.Segura departamento de Quimica Organica I Facultad de CC.QuimicasUniversidad Complutense de Madrid28040 MadridSpain departamento de Quimica Analitica y Analisis Instrumental Facultad de CienciasUniversidad Autónoma de Madrid28049 MadridSpain departamento de Fisica de la Materia Condensada Universidad Autónoma de Madrid28049 MadridSpain Condensed Matter Physics Center(IFIMAC) Universidad Autónoma de Madrid28049 MadridSpain departamento de Nanoestructuras SuperficiesRecubrimientos y Astrofisica MolecularInstituto de Ciencia de Materiales de Madrid(ICMMCSIC)28049 MadridSpain Instituto Madrileno de Estudios Avanzados en Nanociencia(IMdeA-Nanociencia) 28049 MadridSpain Institute for Advanced Research in Chemical Sciences(IAdChem) Universidad Autonoma de Madrid28049 MadridSpain

A novel porous and crystalline two-dimensional(2D)electrochemically active covalent organic framework(COF)based on ortho-quinone units has been prepared as an innovative approach towards the development of organic cathode materials with multiple redox sites as an efficient electrocatalyst for the oxygen reduction reaction(ORR).In contrast with most of the previously reported COFs as electrocatalysts for the ORR,the electrocatalytic application of this material towards ORR has been investigated without adding any metal or conductive supporting material and avoiding any additional carbonization step.Additionally,the electrochemical properties of the COF material have been compared with two analogue amorphous frameworks with similar chemical composition,which points out the important role of the enhanced crystallinity and porosity of the COF network in its superior performance as an electrocatalyst towards ORR.

关键词： electrocatalysis oxygen reduction reaction metal free pyrenetetraone covalent organic framework

Reduction of NO by CO using Pd–CeTb and Pd–CeZr catalysts supported on SiO_2 and La_2O_3–Al_2O_3

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Journal of Environmental Sciences 2015年第1期27卷 87-96页

作者： Victor Ferrer Dora Finol Roger Solano Alexander Moronta Miguel Ramos Instituto de superficies y Catálisis Facultad de Ingeniería Universidad del Zulia Instituto Zuliano de Investigaciones Tecnológicas km 15 carretera Vía a la Ca?ada Apartado 331 Venezuela

The catalytic activity of Pd catalysts supported on Ce0.73Tb0.27Ox/SiO2, Ce0.6Zr0.4Ox/Si O2,Ce0.73Tb0.27Ox/La2O3–Al2O3and Ce0.6Zr0.4Ox/La2O3–Al2O3was studied using the reduction of NO by CO. The catalysts were characterized by X-ray fluorescence, surface area, X-ray diffraction, temperature-programmed reduction, CO chemisorption and oxygen storage capacity. Temperature-programmed reduction results indicated that Tb or Zr incorporation improves the reducibility and oxygen storage capacity. CO chemisorption data suggested the presence of large Pd O particles due to the low CO/Pd ratio. No significant differences were obtained in light off temperatures（T Light off） for all Pd catalysts and the most active was1.5%Pd/Ce0.6Zr0.4Ox/SiO2.

关键词： Mixed oxides OSC Reduction of NO by CO Three way catalysts

Oxidation and Coatings for Power Generation： New Super Ultra Critical Steam Turbines

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中国腐蚀与防护学报 2009年第4期29卷 318-319页

作者： F. J. PEREZ grupo de Investigacion de Ingenieria de superficies y Materiales Nanoestructurados U. C. M. N°910627 Facultad de ciencias Quimicas Universidad Complutense de Madrid. 28040 Madrid Spain

The steels with chromium contents between 9%and 12%wt are used for power plants with advanced steam oxidation conditions.They present good creep properties as 9%Cr steels and good oxidation resistance,at the temperatures range between 500℃～600℃.In the last years numerous investigation in development of coatings has been realized with the aim the protected them against the oxidation in order to allow operation of steam turbines at 650℃.In this study,Al-Hf protective coatings were deposited by CVD-FBR on ferritic steel HCM-12A followed by a diffusion heat treatment,have shown to be protective at 650℃under steam for at least 3000 hours of laboratory steam exposure under atmospheric pressure.Morphology and composition of coatings were characterized by different techniques, such as scanning electron microscopy(SEM),electron probe microanalysis,and X-ray diffraction(XRD). On the other hand,volatile species by mass spectrometry(MS) and thermogravimetric measurements (TG) during the initial stages oxidation of the P92 ferritic steel without and of Al and Al/Si coating by chemical vapour deposition in fluidized bed reactors(CVD-FBR) at 650℃in Ar+20%H_2O for 150 h were studied.In order to go forward to coatings design the Thermocalc code is used as base for the MSdata. TG-MS experiments were conducted in a closed steam loop in order to obtain information about the oxyhydroxides formation as reaction between coatings and steam.From those results the role of the different coating element could be established and optimized for the coating durability.An oxidation mechanism based on the TG-MS results is given.The morphology/composition and structure of the oxidized samples were also studied using SEM/EDS and XRD techniques.

关键词：氧化金属腐蚀防护

NiO-CaO materials as promising catalysts for hydrogen production through carbon dioxide capture and subsequent dry methane reforming

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Journal of Energy Chemistry 2017年第5期26卷 942-947页

作者： Alejandra Cruz-Hernández J.Arturo Mendoza-Nieto Heriberto Pfeiffer Laboratorio de Fisicoquímica y Reactividad de superficies(LaFReS) Instituto de Investigaciones en MaterialesUniversidad Nacional Autónoma de MéxicoCircuito exterior s/nCiudad UniversitariaDel.CoyoacánCP 04510Ciudad de MéxicoMexico

In this work, CaO-NiO mixed oxide powders were evaluated as consecutive CO;chemisorbents and catalytic materials for hydrogen production thought the CH;reforming process. Between the NiO impregnated CaO and CaO-NiO mechanical composite, the first one presented better chemical behaviors during the CO;capture and CH;reforming processes, obtaining syngas（H;+ CO） as final product. Results showed that syngas was produced at two different temperature ranges, between 400 and 600 °C and at T > 800 °C, where the first temperature range corresponds to the CH;reforming process but the second temperature range was attributed to a different catalytic reaction process: CH;partial oxidation. These results were confirmed through different isothermal and cyclic experiments as well as by XRD analysis of the final catalytic products, where the nickel reduction was evidenced. Moreover, when a CO-O;flow was used during the carbonation process a triple process was achieved:（i） CO oxidation,（ii） CO;chemisorption and（iii） CH;reforming. Using this gas flow the hydrogen production was always higher than that obtained with CO;.

关键词： Methane reforming CO2 capture Calcium oxide H2 production NiO supported

Synthesis and evaluation as CO2 chemisorbent of the Li5(Al1-xFex)O4 solid solution materials:Effect of oxygen addition

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Journal of Energy Chemistry 2017年第5期26卷 948-955页

作者： Paulina Olavarría Elizabeth Vera Enrique J.Lima Heriberto Pfeiffer Laboratorio de Fisicoquímica y Reactividad de superficies(LaFReS) Instituto de Investigaciones en MaterialesUniversidad Nacional Autońoma de MexicoCircuito exterior s/nCd.UniversitariaDel.Coyoacan C.P.04510Ciudad de MéxicoMexico

Pentalithium aluminate（β-LiAlO） and the corresponding iron-containing solid solution(Li(AlFe)O)were synthetized by solid-state reaction. All the samples were characterized structural and microstructurally by X-ray diffraction, solid-state nuclear magnetic resonance, scanning electron microscopy, Nadsorption-desorption and temperature-programmed desorption of CO. Results showed that 30 mol% of iron can be incorporated into the β-LiAlOcrystalline structure at aluminum positions. Moreover, iron addition induced morphological and superficial reactivity variations. Li(AlFe)Osamples chemisorbed CObetween 200 and 700 °C, where the superficial chemisorption presented the highest enhancement,in comparison to β-LiAlO. Additionally, Li(AlFe)Osamples sintered at higher temperatures thanβ-LiAlO. Isothermal COchemisorption experiments of β-LiAlOand Li(AlFe)Owere fitted to a first order reaction model, corroborating that iron enhances the COchemisorption, kinetically. When oxygen was added to the gas flow, COchemisorption process was mainly enhanced between 400 and 600 °C for the Li(AlFe)Osample in comparison to β-LiAlO. Hence, Li(AlFe)Osolid solution presented an enhanced COchemisorption process, in the presence and absence of oxygen, in comparison to β-LiAlO.

关键词： Lithium aluminate CO2 chemisorption Solid solution Thermogravimetry

Thermokinetic and conductivity analyzes of the high CO2 chemisorption on Li5AlO4 and alkaline carbonate impregnated Li5AlO4 samples:Effects produced by the use of CO2 partial pressures and oxygen addition

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Journal of Energy Chemistry 2017年第5期26卷 919-926页

作者： Pedro Sánchez-Camacho J.Francisco Gómez-García Heriberto Pfeiffer Laboratorio de Fisicoquímica y Reactividad de superficies(LaFReS) Instituto de Investigaciones en MaterialesUniversidad Nacional Autońoma de MexicoCircuito exterior s/nCd.UniversitariaDel.Coyoacan C.P.04510Ciudad de Me´xicoMexico

The effect of COpartial pressure was evaluated during the COchemisorption in penta lithium aluminate（LiAlO）, using different COand Opartial pressures in the presence or absence of alkaline carbonates. Results showed that using low PO（0.1） did not affect the kinetic and final COchemisorption process. Moreover, small additions of oxygen（PO= 0.05） into the mixture flue gas, seemed to increase the COchemisorption. Additionally, the presence of alkaline carbonates modified the COcapture temperature range. COchemisorption kinetic parameters were determined assuming a double exponential model where direct COchemisorption and COchemisorption controlled by diffusion processes are considered.Finally, ionic diffusion was analyzed by ionic conduction analysis, where all the gravimetric and ionic measurements were in good agreement showing different diffusion processes depending on temperature.Finally, the oxygen and alkaline carbonate additions have positive effects during the COchemisorption process in LiAlO, and a possible reaction mechanism is presented.

关键词： CO2 capture Thermogravimetric analysis Partial pressure Ionic conduction

Structural evolution and reaction mechanism of lithium nickelate(LiNiO_(2))during the carbonation reaction

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Journal of Materiomics 2018年第1期4卷 56-61页

作者： Daniela Gonzalez-Varela Brenda Alcantar-Vazquez Heriberto Pfeiffer Laboratorio de Fisicoquímica y Reactividad de superficies(LaFReS) Instituto de Investigaciones en MaterialesUniversidad Nacional Autonoma de MexicoCircuito exterior s/nCUDel.CoyoacanCP 04510Ciudad de MexicoMexico Instituto de Ingenieria Coordinacion de Ingeniería AmbientalUniversidad Nacional Autonoma de MexicoCircuito Escolar s/nCUDel.CoyoacanCP 04510Ciudad de MexicoMexico

Lithium nickelate(LiNiO_(2))was synthesized using the lithium excess method,and then characterized by X-ray diffraction,scanning electron microscopy and N_(2) adsorption-desorption.Finally,differential thermal and thermogravimetric analyses were performed in CO_(2)presence,at high temperatures.Results show that LiNiO_(2)is able to react with CO_(2)through a complex structural evolution process,where lithium atoms are released to produce Li_(2)CO_(3),while some nickel atoms are rearranged on different Li_(1-x)Ni_(1+x)O_(2)crystalline phases.LiNiO_(2)-CO_(2)reaction kinetic parameters were determined assuming a first-order reaction,where kinetic constants tended to increase as a function of temperature.However,kinetic constant values did not follow a linear trend.This atypical behavior was attributed to LiNiO_(2)sintering and crystalline evolution performed as a function of temperature.

关键词： Lithium nickelate CO_(2)chemisorption Lithium diffusion coefficient Phase transition

Application of 3A Zeolite Prepared from Venezuelan Kaolin for Removal of Pb (II) from Wastewater and Its determination by Flame Atomic Absorption Spectrometry

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American Journal of Analytical Chemistry 2013年第10期4卷 584-593页

作者： Wendy Rondón David Freire Zully de Benzo Angela B. Sifontes Yorbin González Maribel Valero Joaquín L. Brito Laboratorio de Espectroscopia Molecular Facultad de Ciencias Universidad de Los Andes Mérida Venezuela Laboratorio de Fisicoquímica de superficies Centro de Química Instituto Venezolano de Investigaciones Científicas IVIC Caracas Venezuela Laboratorio de Química Analítica Centro de Química Instituto Venezolano de Investigaciones Científicas IVIC Caracas Venezuela

This work consists in the use of a 3A zeolite (K-LTA) obtained by a process of exchange of sodium for potassium (4A zeolite), synthesized from Venezuelan kaolin for the removal of Pb (II) ions from aqueous solutions by batch process mode in order to consider its application in treating industrial wastewaters. The 3A zeolite was characterized for X-ray powder diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR) and scanning electron microscopy and energy dispersive X-ray microanalysis (SEM-EDX). The metal concentration in the equilibrium Ce (mg·L-1) after adsorption with 3A zeolite was analyzed using flame atomic absorption spectrometry (FAAS). The influences of the solution pH, contact time, metal initial concentration and adsorbent dosage have been studied. The retention of metal occurring at pH values around 6.5 and the adsorption equilibrium was obtained at 60 min. The equilibrium process was well described by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. The Langmuir parameters qm (mg·g-1) and b (L·mg-1) (which are related to the sorption capacity and constant of sorption energy) obtained were 14.64 and 5.42 respectively. The Pb (II) experimental uptake was about 14.56 mg·g-1, a little smaller than the theoretical one given by Langmuir isotherm model. The regression parameters and correlation coefficients (R) indicate that the adsorption data for Pb (II) removal fit better the Langmuir isotherm model. Moreover, 0 1/n 1 (1/n is 0.13), indicating that adsorption of metal ions on the zeolite, is a favorable physical process. The application of removing of the metal lead from real samples was examined by industrial wastewater samples. For all samples, the percentage of recovery was found with accuracy of more than 98%. The present work suggests 3A zeolite used as a sorbent material with relatively low cost, obtained from Venezuelan raw material;it is a candidate for removal lead ion and probably other cationic heavy metal species from wastewater.

关键词： Adsorption Wastewater Lead (II) Ion Zeolite Langmuir Isotherm FAAS

Anomalous transport of light at the phase transition to localization:strong dependence with incident angle

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光子学研究：英文版 2018年第10期6卷 929-942页

作者： ERNESTO JIMENEZ-VILLAR M.C.S.XAVIER NIKLAUS U.WETTER VALdeCI MESTRE WELITON S.MARTINS GABRIEL F.BASSO V.A.ERMAKOV F.C.MARQUES GILBERTO F.de SA Instituto de Pesquisas Energeticas e Nucleares CNEN_IPENSao PauloSP 05508-000Brazil departamento de Ffsica Universidade Federal da ParaibaJoao PessoaPB 58051-970Brazil departamento de Fisica Universidade Estadual da ParaibaArarunaPB 58233-000Brazil CCEA Universidade Estadual da ParaibaPatosPB 58706-560Brazil departamento de Fisica Universidade Federal Rural de PernambucoRecifePE 52171-900Brazil departamento de Informatica Universidade Federal da ParaibaJoao PessoaPB 58055-000Brazil departamento de Fisica Aplicada Universidade Estadual de CampinasCampinasSP 13083-859Brazil Quimica Fundamental Universidade Federal de PernambucoRecifePE 50670-901Brazil

There has been a growing interest in disordered optical media in recent years due to their potential applications in solar collectors, random lasers, light confinement, and other advanced photonic functions. This paper studies the transport of light for different incidence angles in a strongly disordered optical medium composed of core-shell TiO_2@Silica nanoparticles suspended in an ethanol solution. A decrease of optical conductance and an increase of absorption near the input border are reported when the incidence angle increases. The specular reflection, measured for the photons that enter the sample, is lower than the effective internal reflection undergone by the coherently backscattered photons in the exact opposite direction, indicating a nonreciprocal propagation of light.This study represents a novel approach in order to understand the complex physics involved at the phase transition to localization.

关键词：光学介质太阳能通讯技术发展现状