Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Titanium dioxide as a catalyst support in heterogeneous catalysis.

ABSTRACT: The lack of stability is a challenge for most heterogeneous catalysts. During operations, the agglomeration of particles may block the active sites of the catalyst, which is believed to contribute to its instability. Recently, titanium oxide (TiO2) was introduced as an alternative support material for heterogeneous catalyst due to the effect of its high surface area stabilizing the catalysts in its mesoporous structure. TiO2 supported metal catalysts have attracted interest due to TiO2 nanoparticles high activity for various reduction and oxidation reactions at low pressures and temperatures. Furthermore, TiO2 was found to be a good metal oxide catalyst support due to the strong metal support interaction, chemical stability, and acid-base property. The aforementioned properties make heterogeneous TiO2 supported catalysts show a high potential in photocatalyst-related applications, electrodes for wet solar cells, synthesis of fine chemicals, and others. This review focuses on TiO2 as a support material for heterogeneous catalysts and its potential applications.

SUBMITTER: Bagheri S

PROVIDER: S-EPMC4213406 | biostudies-other | 2014

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Carbon nanotube-titanium dioxide nanocomposite support for improved activity and stability of an iridium catalyst toward the oxygen evolution reaction.

Project description:In order to improve the electrocatalytic activity and stability of an iridium (Ir) nanoparticle catalyst toward the oxygen evolution reaction (OER) in acidic electrolyte, carbon nanotube and titanium dioxide nanocomposites (CNT@TiO2) are presented as a high-performance support. TiO2 was synthesized on CNTs by using a novel layer-by-layer solution coating method that mimics atomic layer deposition (ALD) but is cost-effective and scalable. In the nanocomposites, CNTs serve as the electron pathways and the surface TiO2 layers protect CNTs from corrosion under the harsh OER conditions. Thus, CNT@TiO2 demonstrates excellent corrosion resistance as well as a high electrical conductivity (1.6 ± 0.2 S cm-1) comparable to that of Vulcan carbon (1.4 S cm-1). The interaction between Ir and TiO2 promotes the formation of Ir(iii) species, thereby enhancing the OER activity and stability of the Ir nanoparticle catalyst. Compared to commercial carbon-supported Ir (Ir/C) and Ir black catalysts, CNT@TiO2-supported Ir exhibits superior OER activity and stability.

| S-EPMC9753482 | biostudies-literature

Glass wool: a novel support for heterogeneous catalysis.

Project description:Heterogeneous catalysis presents significant advantages over homogeneous catalysis such as ease of separation and reuse of the catalyst. Here we show that a very inexpensive, manageable and widely available material - glass wool - can act as a catalyst support for a number of different reactions. Different metal and metal oxide nanoparticles, based on Pd, Co, Cu, Au and Ru, were deposited on glass wool and used as heterogeneous catalysts for a variety of thermal and photochemical organic reactions including reductive de-halogenation of aryl halides, reduction of nitrobenzene, Csp3-Csp3 couplings, N-C heterocycloadditions (click chemistry) and Csp-Csp2 couplings (Sonogashira couplings). The use of glass wool as a catalyst support for important organic reactions, particularly C-C couplings, opens the opportunity to develop economical heterogeneous catalysts with excellent potential for flow photo-chemistry application.

| S-EPMC6114997 | biostudies-literature

Titanium dioxide nanoparticles exposure

2010-12-22 | GSE17902 | GEO

Classical strong metal-support interactions between gold nanoparticles and titanium dioxide.

Project description:Supported metal catalysts play a central role in the modern chemical industry but often exhibit poor on-stream stability. The strong metal-support interaction (SMSI) offers a route to control the structural properties of supported metals and, hence, their reactivity and stability. Conventional wisdom holds that supported Au cannot manifest a classical SMSI, which is characterized by reversible metal encapsulation by the support upon high-temperature redox treatments. We demonstrate a classical SMSI for Au/TiO2, evidenced by suppression of CO adsorption, electron transfer from TiO2 to Au nanoparticles, and gold encapsulation by a TiO x overlayer following high-temperature reduction (reversed by subsequent oxidation), akin to that observed for titania-supported platinum group metals. In the SMSI state, Au/TiO2 exhibits markedly improved stability toward CO oxidation. The SMSI extends to Au supported over other reducible oxides (Fe3O4 and CeO2) and other group IB metals (Cu and Ag) over titania. This discovery highlights the general nature of the classical SMSI and unlocks the development of thermochemically stable IB metal catalysts.

| S-EPMC5640381 | biostudies-literature

Photocatalytic Indole Diels-Alder Cycloadditions Mediated by Heterogeneous Platinum-Modified Titanium Dioxide.

Project description:Indole alkaloids represent an important class of molecules, with many naturally occurring derivatives possessing significant biological activity. One area that requires further development in the synthesis of indole derivatives is the Diels-Alder reaction. In this work, we expand on our previously developed heterogeneous protocol for the [4+2] cycloaddition of indoles and electron-rich dienes mediated by platinum nanoparticles supported on titanium dioxide semiconductor particles (Pt(0.2%)@TiO2) with visible-light irradiation. This reaction proceeds with broad scope and is more efficient per incident photon than the previous homogeneous method, and the catalyst can be easily recycled and reused.

| S-EPMC5663233 | biostudies-other

Titanium dioxide nanoparticles exposure

Project description:This project utilized oligonucleotide microarrays to examine gene expression patterns in adult male fathead minnows (Pimephales promelas) exposed to a common nanomaterial, titanium dioxide (TiO2, stearate-coated particles, MT-100TV®). We exposed adult male fathead minnows for 96 hr to three doses (0, 1, and 10 mg/L nominal) of TiO2 under static renewal conditions. TiO2 is stearate coated, 15 nm particle size. Three-condition experiment: high dose, controls (untreated, low dose). Three tissues: liver, gill, brain. Biological replicates: 4 control replicates, 4 low dose, 4 high dose for gill and liver. One array for brain control and low dose; and 2 arrays for brain high dose. Contributor: Johnson & Johnson Worldwide Envrionmental

2010-12-22 | E-GEOD-17902 | biostudies-arrayexpress

The Role of Catalyst Support, Diluent and Co-Catalyst in Chromium-Mediated Heterogeneous Ethylene Trimerisation.

Project description:Sequential treatment of a previously-calcined solid oxide support (i.e. SiO2, γ-Al2O3, or mixed SiO2-Al2O3) with solutions of Cr{N(SiMe3)2}3 (0.71 wt% Cr) and a Lewis acidic alkyl aluminium-based co-catalyst (15 molar equivalents) affords initiator systems active for the oligomerisation and/or polymerisation of ethylene. The influence of the oxide support, calcination temperature, co-catalyst, and reaction diluent on both the productivity and selectivity of the immobilised chromium initiator systems have been investigated, with the best performing combination (SiO2-600, modified methyl aluminoxane-12 {MMAO-12}, heptane) producing a mixture of hexenes (61 wt%; 79% 1-hexene), and polyethylene (16 wt%) with an activity of 2403 g gCr -1 h-1. The observed product distribution is rationalised by two competing processes: trimerisation via a supported metallacycle-based mechanism and polymerisation through a classical Cossee-Arlman chain-growth pathway. This is supported by the indirect observation of two distinct chromium environments at the surface of the oxide support by a solid-state 29Si NMR spectroscopic study of the Cr{N(SiMe3)2}x/SiO2-600 pro-initiator.

| S-EPMC6413812 | biostudies-literature

Plasma-Induced Catalyst Support Defects for the Photothermal Methanation of Carbon Dioxide.

Project description:The presence of defects in a catalyst support is known to benefit catalytic activity. In this work, a He-plasma treatment-based strategy for introducing and stabilising defects on a Ni/TiO2 catalyst for photothermal CO2 hydrogenation was established. The impact of pretreatment step sequence-which comprised He-plasma treatment and reduction/passivation-on defect generation and stabilisation within the support was evaluated. Characterisation of the Ni/TiO2 catalysts indicated that defects created in the TiO2 support during the initial plasma treatment stage were then stabilised by the reduction/passivation process, (P-R)Ni/TiO2. Conversely, performing reduction/passivation first, (R-P)Ni/TiO2, invoked a resistance to subsequent defect formation upon plasma treatment and consequently, poorer photothermal catalytic activity. The plasma treatment altered the metal-support interaction and ease of catalyst reduction. Under photothermal conditions, (P-R)Ni/TiO2 reached the highest methane production in 75 min, while (R-P)Ni/TiO2 required 165 min. Decoupling the impacts of light and heat indicated thermal dominance of the reaction with CO2 conversion observed from 200 °C onwards. Methane was the primary product with carbon monoxide detected at 350 °C (~2%) and 400 °C (~5%). Overall, the findings demonstrate the importance of pretreatment step sequence when utilising plasma treatment to generate active defect sites in a catalyst support.

| S-EPMC8347005 | biostudies-literature

Photocatalytic degradation of methylene blue with spent FCC catalyst loaded with ferric oxide and titanium dioxide.

Project description:The spent fluid catalytic cracking (FCC) catalyst has been loaded with ferric oxide (Fe2O3) and titanium dioxide (TiO2). Fe-Ti/SF composite (loaded with 5 wt% TiO2 and 5 wt% Fe2O3), Fe/SF composite (loaded with10 wt% Fe2O3) and Ti/SF composite (loaded with 10 wt% TiO2) have been fabricated via a modified-impregnation method. The band gaps of the Fe-Ti/SF, Fe/SF and Ti/SF composites (evaluated by the energy versus [F(R∞)hv]n) are 2.23, 1.98 and 3.0 eV, respectively. Electrochemical impedance spectroscopy shows that the Fe-Ti/SF has lower electron transfer resistance, it has the small charge transfer resistance and fast charge transfer rate. The interparticle electrons transfer between the Fe2O3 and TiO2, which can improve the separation of the photo-electrons and holes. The holes transfer from valence band of TiO2 to the valence band of Fe2O3, which can provide more active sites around the adsorbed molecules. The methylene blue degradation efficiencies (with the Fe-Ti/SF, Fe/SF and Ti/SF composites) are ~ 94.2%, ~ 22.3% and ~ 54.0% in 120 min, respectively. This work reveals that the spent FCC catalyst as supporter can be loaded with Fe2O3 and TiO2. This composite is highly suitable for degradation of methylene blue, which can provide a potential method to dispose the spent FCC catalyst in industry.

| S-EPMC7391759 | biostudies-literature

Homogeneous Catalysis and Heterogeneous Recycling: A Simple Zn(II) Catalyst for Green Fatty Acid Esterification.

Project description:This work describes the use of simple zinc(II) salts (ZnCl2, ZnCO3, Zn(OAc)2, ZnO, Zn(ClO4)2, Zn(TfO)2, and Zn(BF4)2) as effective catalysts for the esterification of fatty acids with long-chain alcohols and simple polyols through a homogeneous system that allows the gradual and selective removal of water. The results show that the catalytic activity depends on the nature of the counterion: the most effective are the salts with poorly coordinating anions (perchlorate and triflate) or containing basic Brønsted anions (oxide, acetate, and carbonate). However, only with the latter is it possible to fully recover the catalyst at the end of each run, which is easily filtered in the form of zinc carboxylate, given its insolubility in the ester produced. In this way, it is possible to recycle the catalyst numerous times, without any loss of activity. This beneficial prerogative couples the efficiency of the homogeneous catalysis with the advantage of the heterogeneous catalysis. The process is, therefore, truly sustainable, given its high efficiency, low energy consumption, ease of purification, and the absence of auxiliary substances and byproducts.

| S-EPMC8297397 | 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