Francisco José Pérez-Alonso

• PhD
• Senior Researcher at Centro Ibérico de Investigación en Almacenamiento de Energía

Ru-Co/Al2O3 and Ru-Fe/Al2O3 have been prepared by the reduction-deposition method. This approach favours the interaction between Ru and Fe or Co in the final catalysts, while increasing surface enrichment of Ru. Their performance for the Fischer-Tropsch Synthesis (FTS) has been evaluated in a fixed bed reactor. Ru-Co/Al2O3 displays the highest acti...

This article describes the current state of the art in the development of high energy density, rechargeable and safe aluminium batteries, which at the same time are cheap and easy to manufacture. This is one of Europe’s most important scientific and technological challenges in the medium term. Together with lithium, a strong research effort is bein...

A first study that demonstrates the capability of the amino-functionalized MCM-41 sorbents to reduce Cr(VI) to the less toxic trivalent state is presented. To achieve this aim two mesoporous ordered silica with MCM-41 pores arrangement were synthesized and surface modified by a post-synthetic treatment using 3-aminopropyltriethoxysilane in toluene....

LaNiO3 perovskite is a promising electrocatalyst for the oxygen reduction reaction (ORR). In this work we study the effects of several key structural and morphological features on the performance of LaNiO3 perovskites for the ORR. We have prepared a series of LaNiO3 oxides via soft chemistry and calcined the final materials at different temperature...

Fe/N/C catalysts are very active for the oxygen reduction reaction (ORR); however, the nature of the active site(s) is not fully understood. In this work, we study the performance of different types of N/C and Fe/N/C catalysts for the ORR, and the effect of the addition of NaCN. Phthalocyanine and graphene have been studied as model metal-free cata...

The optimization of the synthesis of Fe/N/G catalysts for the oxygen reduction reaction (ORR) has been investigated. The synthesis of Fe/N/G comprises a solid state reaction of the precursors in a planetary ballmilling followed by a thermal treatment in ammonia/nitrogen atmosphere. First, the influence of the concentration of NH3 during the pyrolys...

The Fischer-Tropsch synthesis (FTS) is an appealing process to generate liquid fuels from syngas. The elusive nature of FTS active sites is clarified here through a comprehensive theoretical-experimental study of CO dissociation on supported Ru catalysts. Our theoretical calculations show that boron (B) adsorption is stronger than that of CO on ste...

The electrooxidation of ethanol and acetaldehyde on Pt/C has been studied by using in situ IR spectroscopy. To identify the species formed during the electrooxidation reactions accurately, the IR spectra were collected in both HClO4/H2O and HClO4/D2O electrolytes. The results shown herein reveal that ethanol adsorbs on Pt at low potentials in a ser...

In this work a series of N-modified graphene composites with different N/C ratios have been synthesised. The incorporation of Fe atoms into the N-modified graphene composites leads to the formation of Fe/N/C ensembles on the outer graphene layers along with Fe3C and metallic Fe phases in the bulk of the graphite nanoplates as revealed by X-ray abso...

The effect of the addition of Cl to Ru/γ-Al2O3 catalysts for the Fischer-Tropsch synthesis has been investigated. A series of four catalysts containing 3 wt.% of Ru supported on γ-Al2O3 and promoted with different amounts of chlorine (Cl/Ru atomic ratios of 0, 1, 5 and 10) has been prepared. The catalysts were tested in the Fischer Tropsch synthesi...

The H2-distributed feeding concept using Pd/Ag-based membranes and an Ru-based catalyst in a Packed Bed Membrane Reactor (H2-PBMR) for the synthesis of biofuels via the so-called Fischer-Tropsch Synthesis has been demonstrated. The most successful approach resulted when H2-poor syngas (H2/CO=1) typically obtained from the gasification of biomass wa...

The co-incorporation of S and N into multiwalled carbon nanotubes (CNTs) and the effects for the catalytic performance for the oxygen reduction reaction (ORR) in acidic and alkaline electrolytes has been studied. Subjecting CNTs to different ballmilling periods results in the formation of defects in their graphitic structure. Heteroatoms such as N...

Nickel–cobalt based electrodes with different Ni–Co ratios have been prepared by electroless-plating deposition from NiSO4 and CoSO4 solutions. The performance of the electrodes for the HER and OER reactions has been examined by linear sweep voltammetry. The electrode containing only nickel (Ni-ELP) displays the lowest overpotential for the HER. On...

This work assesses the effect of the particle size for the Fischer–Tropsch synthesis with catalysts based on Ru particles between 4 and 71 nm. CO dissociation is a structure-sensitive reaction, that is, the turnover frequency (TOF) is affected by Ru particle size. Herein it is demonstrated that two regimes exist for the effect of Ru particle size....

Monodispersed Pt3Sn nanoparticles were prepared through a mild thermal synthesis in the presence of surfactants. The performance of Pt3Sn for the electrooxidation of ethanol and adsorbed carbon monoxide (COad) in acid medium was studied by a combination of electrochemical and in situ spectroscopic methods, namely, infrared reflection absorption spe...

The inside cover picture depicts how Pt catalysts are able to break the CC bond of the ethanol molecule leading to C1,ad species, which actually poison the catalysts. Going to more positive potentials makes it possible to remove such species by oxidizing them. The surface an oxophilic particle such as Pt3Sn is already covered by OHad, even at low p...

A series of Ni/Fe electrodes have been prepared by electrodeposition of metal salt precursors on different substrates. The surface morphology, chemical composition and electrochemical characteristics of these electrodes were studied by various physico-chemical techniques such as X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscop...

The effect of the metal for the oxygen reduction reaction (ORR) in acid medium with nonprecious metal catalysts has been investigated. A series of non-precious metal catalysts with typical formulation M/N/C with M being Mn, Co or Fe have been prepared by incorporating N onto an active carbon matrix by means of thermal treatments under inert atmosph...

New technologies aimed to reduce the huge amounts of anthropogenic CO2 emissions and their environmental impacts would only succeed if the product resulting from the transformation of CO2 is demanded in high quantities, as for instance, methanol. In this context, we have undertaken a systematic study of the catalytic hydrogenation of CO2 into metha...

I could never be without Cu: An active site has been designed for the catalysis of CO electroxidation. This was achieved by incorporating submonolayer amounts of Cu (orange shperes) into a single crystal of Pt (gray spheres). The electrochemical reactivity of this surface was highly sensitive to the exact position of Cu.

Nanosized nickel particles have been synthesized by three different routes: polyol, microemulsion and precipitation/reduction methods. Nickel nanoparticles have been evaluated as electrocatalysts for the hydrogen evolution reaction (HER). The electrocatalysts have been characterized by using X-ray diffraction (XRD), thermogravimetric analysis (TGA)...

A matter of size: The particle size effect on the activity of the oxygen reduction reaction of size-selected platinum clusters was studied. The ORR activity decreased with decreasing Pt nanoparticle size, corresponding to a decrease in the fraction of terraces on the surfaces of the Pt nanoparticles (j(k) =kinetic current density, see picture).

The degradation mechanisms of Pt nanoparticles supported on Carbon have been characterized during oxygen reduction reaction (ORR) conditions using IL-TEM. A TEM grid is used as the sole working electrode allowing a direct correlation between the electrochemical response and the TEM analysis. We mainly observe a decrease in nanoparticle size with so...

The effect of mesostructuration of beta zeolite and of metal loading on the properties of cobalt-based catalysts for Fischer–Tropsch synthesis was studied in this work. The most active catalyst was the mesostructured beta zeolite-supported cobalt (10%), which also showed a low selectivity to methane and the lowest olefin/paraffin ratio. KeywordsFi...

The Pt(111)/electrolyte interface has been characterized during the oxygen reduction reaction (ORR) in 0.1 M HClO(4) using electrochemical impedance spectroscopy. The surface was studied within the potential region where adsorption of OH* and O* species occur without significant place exchange between the adsorbate and Pt surface atoms (0.45-1.15 V...

To enable the development of low temperature fuel cells, significant improvements are required to the efficiency of the Pt electrocatalysts at the cathode, where oxygen reduction takes place. Herein, we study the effect of subsurface solute metals on the reactivity of Pt, using a Cu/Pt(111) near-surface alloy. Our investigations incorporate electro...

A relationship between the chemical state of Ru on bimetallic PtRu bulk samples and their performance in both CO and methanol electrooxidation has been established. The nature of the Ru species in the bimetallic samples has been scrutinized by means of XPS, XRD and TPR. The following Ru species were detected; reduced ruthenium (Ru0), anhydrous RuO2...

Several Fe-Ce catalysts for FT synthesis were prepared following two different methods: coprecipitation from Fe and Ce nitrate solutions and a physical mixture of pure Fe and Ce oxide precursors. Previously to CO hydrogenation, catalysts were activated in syngas (50 ml/min, H 2 /CO = 2) at 553 K for 1 h at atmospheric pressure. The iron phases de-v...

Unpromoted and Ce-promoted Fe catalysts were tested in the CO2 hydrogenation reaction. Both catalysts form predominantly CO and hydrocarbons (C1–C10). Reaction rate and selectivity to the different products were essentially the same with both catalysts. The chain growth probability (α) was very similar in both cases (∼0.44). Prior of being used in...

A series of Fe-Ce mixed oxides (95 atom % Fe-5 atom % Ce) has been prepared by different methods: coprecipitation, impregnation, and physical mixture of Ce and Fe oxides. These solids have been tested in the Fischer-Tropsch synthesis. The characterization of the catalytic precursors was carried out by X-ray diffraction (XRD), Raman, Mössbauer, and...

A series of iron-based Fischer–Tropsch catalysts, either pure or promoted with Ce or Mn, were subjected to different activation treatments with H 2 , CO, or H 2 /CO. The surface species formed after different treatments were characterized by temperature-programmed surface reaction with hydrogen (TPSR-H 2) and temperature-programmed surface desorpti...

The microemulsion technology was used in order to improve the preparation of iron-based catalysts for the CO and CO2 hydrogenation reactions. This technique led to a sample with a higher surface area when compared with a similar solid prepared by conventional precipitation. As a consequence, a higher catalytic activity was obtained.The hydrogenatio...

A series of silica-supported iron samples has been prepared by the microemulsion technology. The samples were characterized by temperature programmed reduction (TPR), UV–vis spectroscopy, N2 adsorption isotherms, X-ray photoelectron spectra (XPS), SEM and transmission electron microscopy (TEM) microscopy and tested in the carbon monoxide and carbon...

Fe–Ce mixed oxides prepared by coprecipitation showed considerable synergy in N2O decomposition when compared with pure metal oxide counterparts. The mixed system also displayed higher stability in reaction at high temperature. Through characterisation by XRD, XPS and TPR, the activity–stability improvement is ascribed to the formation of Fe-doped...

Several silylated- and nonsilylated Co/SiO2 catalysts have been prepared by reaction of the surface silanol groups with hexamethyldisilazane (HMDS). These samples have been characterized by means of N2 adsorption isotherms, solid-state nuclear magnetic resonance (29Si and 1H), X-ray photoelectron spectroscopy, thermogravimetric analysis, and diffus...

Lanthana- and magnesia-supported nickel catalysts with Ni-loading ranging from 10 to 30 wt.% and calcined at temperatures 1073–1273 K are prepared and tested in the catalytic partial oxidation of methane. These catalysts are characterized by means of X-ray diffraction (XRD), N2 adsorption–desorption measurements, temperature-programmed reduction (T...

Several Fe-Ce catalysts for FT synthesis were prepared following two different methods: coprecipitation from Fe and Ce nitrate solutions and a physical mixture of pure Fe and Ce precursors. The iron phases present in the activated catalysts were identified by XRD and Moessbauer spectroscopy. A good correlation between both techniques was found. The...

Two series of Fe−Ce catalysts were prepared following two different methods:  coprecipitation from Fe and Ce nitrate solutions and physical mixing of pure Fe and Ce precursors. Evidence of the presence of a chemical interaction between Fe and Ce was found in the calcined state of the coprecipitated catalysts. Such evidence was obtained with differe...

Several alumina-supported rhodium-based catalysts have been prepared using the microemulsion technology. The change of microemulsion properties led to catalysts with different Rh particle size and narrow size distribution while keeping the same metal loading. The metal particle size was determined by XRD and TEM. These catalysts were tested in the...

Cylindrical carbon fibre microelectrodes (CFMEs) (8 mm in diameter, 8 mm in length) were used to develop voltammetric methods for the determination of the antioxidant 4-tert-butylcatechol (TBC) in styrene, and of styrene in polystyrene samples. Acetone, containing 0.01 mol l−1 sodium perchlorate as supporting electrolyte, was selected as a sui...

Fe–Ce mixed oxides prepared by coprecipitation showed considerable synergy in N 2 O decomposition when compared with pure metal oxide counterparts. The mixed system also displayed higher stability in reaction at high temperature. Through characterisation by XRD, XPS and TPR, the activity–stability improvement is ascribed to the formation of Fe-dope...

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Física Aplicada. Fecha de lectura 21-09-2006 Bibliografía