Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Laser-Assisted Production of Carbon-Encapsulated Pt-Co Alloy Nanoparticles for Preferential Oxidation of Carbon Monoxide.

ABSTRACT: C-encapsulated highly pure PtxCoy alloy nanoparticles have been synthesized by an innovative one-step in-situ laser pyrolysis. The obtained X-ray diffraction pattern and transmission electron microscopy images correspond to PtxCoy alloy nanoparticles with average diameters of 2.4 nm and well-established crystalline structure. The synthesized PtxCoy/C catalyst containing 1.5 wt% of PtxCoy nanoparticles can achieve complete CO conversion in the temperature range 125-175°C working at weight hourly space velocities (WHSV) of 30 L h-1g-1. This study shows the first example of bimetallic nanoalloys synthesized by laser pyrolysis and paves the way for a wide variety of potential applications and metal combinations.

SUBMITTER: Martinez G

PROVIDER: S-EPMC6198107 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Laser-Assisted Production of Carbon-Encapsulated Pt-Co Alloy Nanoparticles for Preferential Oxidation of Carbon Monoxide.

Martinez Gema G Malumbres Ana A Lopez Angela A Mallada Reyes R Hueso Jose L JL Santamaria Jesus J

Frontiers in chemistry 20181016

C-encapsulated highly pure PtxCoy alloy nanoparticles have been synthesized by an innovative one-step in-situ laser pyrolysis. The obtained X-ray diffraction pattern and transmission electron microscopy images correspond to PtxCoy alloy nanoparticles with average diameters of 2.4 nm and well-established crystalline structure. The synthesized PtxCoy/C catalyst containing 1.5 wt% of PtxCoy nanoparticles ...[more]

PMID: 30386771

Similar Datasets

Highly stable preferential carbon monoxide oxidation by dinuclear heterogeneous catalysts.

Project description:Atomically dispersed catalysts have been shown highly active for preferential oxidation of carbon monoxide in the presence of excess hydrogen (PROX). However, their stability has been less than ideal. We show here that the introduction of a structural component to minimize diffusion of the active metal center can greatly improve the stability without compromising the activity. Using an Ir dinuclear heterogeneous catalyst (DHC) as a study platform, we identify two types of oxygen species, interfacial and bridge, that work in concert to enable both activity and stability. The work sheds important light on the synergistic effect between the active metal center and the supporting substrate and may find broad applications for the use of atomically dispersed catalysts.

| S-EPMC9910598 | biostudies-literature

Formation of Pt-Based Alloy Nanoparticles Assisted by Molybdenum Hexacarbonyl.

Project description:We report on an optimized, scalable solution-phase synthetic procedure for the fabrication of fine-tuned monodisperse nanostructures (Pt(NiCo), PtNi and PtCo). The influence of different solute metal precursors and surfactants on the morphological evolution of homogeneous alloy nanoparticles (NPs) has been investigated. Molybdenum hexacarbonyl (Mo(CO)6) was used as the reductant. We demonstrate that this solution-based strategy results in uniform-sized NPs, the morphology of which can be manipulated by appropriate selection of surfactants and solute metal precursors. Co-surfactants (oleylamine, OAm, and hexadecylamine, HDA) enabled the development of a variety of high-index faceted NP morphologies with varying degrees of curvatures while pure OAm selectively produced octahedral NP morphologies. This Mo(CO)6-based synthetic protocol offers new avenues for the fabrication of multi-structured alloy NPs as high-performance electrocatalysts.

| S-EPMC8308230 | biostudies-literature

Facile fabrication of Cu-based alloy nanoparticles encapsulated within hollow octahedral N-doped porous carbon for selective oxidation of hydrocarbons.

Project description:Hollow carbon materials with versatile chemical compositions and complicated shell architectures hold great promise in heterogeneous catalysis. However, it is a daunting challenge to synthesize metal alloy nanoparticles (NPs) supported by hollow nanostructures. Herein, we present a simple approach for facile fabrication of Pd-Cu alloy NPs embedded in hollow octahedral N-doped porous carbon (Pd-Cu@HO-NPC). The hollow material is derived from HKUST-1 coated by an imidazolium-based ionic polymer (ImIP). Water-sensitive HKUST-1 is simultaneously removed in the process of anion exchange between bromide in the ImIP shell and tetrachloropalladate in aqueous medium. The released Cu(ii) ions and exchanged Pd(ii) ions serve as Cu and Pd sources in the subsequent pyrolysis. The resultant Pd-Cu@HO-NPC exhibits high catalytic activity, selectivity, stability and recyclability in the aerobic oxidation of hydrocarbons. More attractively, the synthetic strategy is of excellent generality, and could be extended to the synthesis of Cu-based bimetallic and trimetallic alloy NPs, such as Pt-Cu@HO-NPC and Pd-Pt-Cu@HO-NPC. This work highlights the superiority of water-sensitive metal-organic frameworks in the ingenious design of hollow carbon materials incorporated with well-dispersed metal alloy NPs.

| S-EPMC6263394 | biostudies-literature

Ligand Fluorination to Optimize Preferential Oxidation (PROX) of Carbon Monoxide by Water-Soluble Rhodium Porphyrins.

Project description:Catalytic, low temperature preferential oxidation (PROX) of carbon monoxide by aqueous [5,10,15,20-tetrakis(4-sulfonatophenyl)-2,3,7,8,12,13,17,18-octafluoroporphyrinato]rhodium(III) tetrasodium salt, (1[Rh(III)]) and [5,10,15,20-tetrakis(3-sulfonato-2,6-difluorophenyl)-2,3,7,8,12,13,17,18-octafluoroporphyrinato]rhodium(III) tetrasodium salt, (2[Rh(III)]) is reported. The PROX reaction occurs at ambient temperature in buffered (4 ? pH ? 13) aqueous solutions. Fluorination on the porphyrin periphery is shown to increase the CO PROX reaction rate, shift the metal centered redox potentials, and acidify ligated water molecules. Most importantly, ?-fluorination increases the acidity of the rhodium hydride complex (pK(a) = 2.2 ± 0.2 for 2[Rh-D]); the dramatically increased acidity of the Rh(III) hydride complex precludes proton reduction and hydrogen activation near neutral pH, thereby permitting oxidation of CO to be unaffected by the presence of H(2). This new fluorinated water-soluble rhodium porphyrin-based homogenous catalyst system permits preferential oxidation of carbon monoxide in hydrogen gas streams at 308 °K using dioxygen or a sacrificial electron acceptor (indigo carmine) as the terminal oxidant.

| S-EPMC3176635 | biostudies-literature

Room-temperature carbon monoxide oxidation by oxygen over Pt/Al2O3 mediated by reactive platinum carbonates.

Project description:Room-temperature carbon monoxide oxidation, important for maintaining clean air among other applications, is challenging even after a century of research into carbon monoxide oxidation. Here we report using time-resolved diffuse reflectance infrared spectroscopy, X-ray absorption fine structure spectroscopy and mass spectrometry a platinum carbonate-mediated mechanism for the room-temperature oxidation of carbon monoxide. By applying a periodic reduction-oxidation mode of operation we further show that this behaviour is reversible and can be formed into a catalytic cycle that requires molecular communication between metallic platinum nanoparticles and highly dispersed oxidic platinum centres. A new possibility for the attainment of low-temperature oxidation of carbon monoxide is therefore demonstrated.

| S-EPMC4846310 | biostudies-literature

Impact of Nanoparticle-Support Interactions in Co3O4/Al2O3 Catalysts for the Preferential Oxidation of Carbon Monoxide.

Project description:Different supporting procedures were followed to alter the nanoparticle-support interactions (NPSI) in two Co3O4/Al2O3 catalysts, prepared using the reverse micelle technique. The catalysts were tested in the dry preferential oxidation of carbon monoxide (CO-PrOx) while their phase stability was monitored using four complementary in situ techniques, viz., magnet-based characterization, PXRD, and combined XAS/DRIFTS, as well as quasi in situ XPS, respectively. The catalyst with weak NPSI achieved higher CO2 yields and selectivities at temperatures below 225 °C compared to the sample with strong NPSI. However, relatively high degrees of reduction of Co3O4 to metallic Co were reached between 250 and 350 °C for the same catalyst. The presence of metallic Co led to the undesired formation of CH4, reaching a yield of over 90% above 300 °C. The catalyst with strong NPSI formed very low amounts of metallic Co (less than 1%) and CH4 (yield of up to 20%) even at 350 °C. When the temperature was decreased from 350 to 50 °C under the reaction gas, both catalysts were slightly reoxidized and gradually regained their CO oxidation activity, while the formation of CH4 diminished. The present study shows a strong relationship between catalyst performance (i.e., activity and selectivity) and phase stability, both of which are affected by the strength of the NPSI. When using a metal oxide as the active CO-PrOx catalyst, it is important for it to have significant reduction resistance to avoid the formation of undesired products, e.g., CH4. However, the metal oxide should also be reducible (especially on the surface) to allow for a complete conversion of CO to CO2 via the Mars-van Krevelen mechanism.

| S-EPMC7011734 | biostudies-literature

Dealloying of Nitrogen-Introduced Pt-Co Alloy Nanoparticles: Preferential Core-Shell Formation with Enhanced Activity for Oxygen Reduction Reaction.

Project description:Voltammetric dealloying is a typical method to synthesize Pt-shell/less-noble metal (M) alloy core nanoparticles (NPs) toward the oxygen reduction reaction (ORR). The pristine nanostructures of the Pt-M alloy NPs should determine the ORR activity of the dealloyed NPs. In this study, we investigated the voltammetric dealloying behavior of the Pt-Co and nitrogen-introduced Pt-Co alloy NPs generated by synchronous arc-plasma deposition of Pt and Co. The results showed that the dealloying behavior is sensitive to cobalt nitride in the pristine NPs, leading to the preferential generation of a Pt-rich shell/Pt-Co alloy core architecture having enhanced ORR activity.

| S-EPMC6640784 | biostudies-literature

Carbon Monoxide-Sensing Transcription Factors: Regulators of Microbial Carbon Monoxide Oxidation Pathway Gene Expression.

Project description:Carbon monoxide (CO) serves as a source of energy and carbon for a diverse set of microbes found in anaerobic and aerobic environments. The enzymes that bacteria and archaea use to oxidize CO depend upon complex metallocofactors that require accessory proteins for assembly and proper function. This complexity comes at a high energetic cost and necessitates strict regulation of CO metabolic pathways in facultative CO metabolizers to ensure that gene expression occurs only when CO concentrations and redox conditions are appropriate. In this review, we examine two known heme-dependent transcription factors, CooA and RcoM, that regulate inducible CO metabolism pathways in anaerobic and aerobic microorganisms. We provide an analysis of the known physiological and genomic contexts of these sensors and employ this analysis to contextualize known biochemical properties. In addition, we describe a growing list of putative transcription factors associated with CO metabolism that potentially use cofactors other than heme to sense CO.

| S-EPMC10210986 | biostudies-literature

Super-Branched PdCu Alloy for Efficiently Converting Carbon Dioxide to Carbon Monoxide.

Project description:The alloying of noble metals with Cu is one of the most effective strategies for improving catalytic performance and reducing cost in electrocatalytic carbon dioxide reduction reactions (CO2RR). Previous works usually focused on the influence of morphology and composition on the catalytic activity, but lacked the study of the valence state ratio of metals and the electron transfer behavior on alloys. In this work, PdCu-2 alloy (Pd/Cu molar ratio is 1:2) was obtained by a simple one-step solvothermal method, which can effectively convert CO2 to CO with a maximum Faradaic efficiency (FE) of 85% at -0.9 V (vs. RHE). Then, the effect of the chemical state of Pd and Cu on the catalytic performance was investigated. The X-ray photoelectron spectroscopy (XPS) shows that the binding energy of Pd in PdCu alloy has a negative shift, which has affected the adsorption of key intermediates. When the proportion of oxidized state and zero-valent metal in the alloy is about 1:2, the PdCu alloy shows the best catalytic activity. In addition, the transient photovoltage (TPV) measurements further demonstrate that due to the introduction of Cu, the electron transfer rate of PdCu-2 becomes the slowest, which helps the accumulation of electrons on PdCu-2 and leads to the improvement of catalytic performance for electrocatalytic CO2RR. This work can provide more insights into the alloy catalysts of electrocatalytic CO2RR.

| S-EPMC9921487 | biostudies-literature

Nanocomposite Concept for Electrochemical In Situ Preparation of Pt-Au Alloy Nanoparticles for Formic Acid Oxidation.

Project description:Herein, we report a straightforward approach for the in situ preparation of Pt-Au alloy nanoparticles from Pt + xAu/C nanocomposites using monometallic colloidal nanoparticles as starting blocks. Four different compositions with fixed Pt content and varying Pt to Au mass ratios from 1:1 up to 1:7 were prepared as formic acid oxidation reaction (FAOR) catalysts. The study was carried out in a gas diffusion electrode (GDE) setup. It is shown that the presence of Au in the nanocomposites substantially improves the FAOR activity with respect to pure Pt/C, which serves as a reference. The nanocomposite with a mass ratio of 1:5 between Pt and Au displays the best performance during potentiodynamic tests, with the electro-oxidation rates, overpotential, and poisoning resistance being improved simultaneously. By comparison, too low or too high Au contributions in the nanocomposites lead to an unbalanced performance in the FAOR. The combination of operando small-angle X-ray scattering (SAXS), scanning transmission electron microscopy (STEM) elemental mapping, and wide-angle X-ray scattering (WAXS) reveals that for the nanocomposite with a 1:5 mass ratio, a conversion between Pt and Au from separate nanoparticles to alloy nanoparticles occurs during continuous potential cycling in formic acid. By comparison, the nanocomposites with lower Au contents, for example, 1:2, exhibit less in situ alloying, and the concomitant performance improvement is less pronounced. On applying identical location transmission electron microscopy (IL-TEM), it is revealed that the in situ alloying is due to Pt dissolution and re-deposition onto Au as well as Pt migration and coalescence with Au nanoparticles.

| S-EPMC9327087 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data