Cell Isolation and Systems Analysis

The Cell Isolation and Systems Analysis (CISA) capability provides technologies and expertise to study individual cells and cell communities or tissues at the molecular level. Live cells or organelles can be isolated from complex populations, including environmental microbial communities or plant tissues for analyses spanning quantitative live cell fluorescence imaging with single molecule sensitivity, super resolution fluorescence and atomic force microscopy, and transcriptomic analyses using next-generation sequencing technologies.  See a complete list of CISA instruments.

Together with proteomics, metabolomics, and electron and ion microscopy, these capabilities provide the foundation for attaining a molecular-level understanding of individual cells and cell community dynamics and function to support biofuel research, understand the role of biological systems in carbon cycling, and enable research in biodefense and other national needs. 

Resources and Techniques

High-resolution quantitative fluorescence microscopy in living cells – use multi-photon, confocal, single-molecule and super resolution fluorescence microscopy, including STORM/PALM coupled with atomic force microscopy and structured illumination microscopy (SIM), fluorescence resonance energy transfer (FRET) and fluorescence lifetime imaging (FLIM) in intact cells.

Cell and organelle isolation – use the Influx™ flowcytometer cell sorter, and a high-resolution laser capture microdissection microscope for isolating distinct cell populations or single cells and organelles from complex microbial communities or tissues for further analyses.

Transcriptomics – use the SOLiD® 5500 series next-generation sequencing systems together with the Ion Proton™ system for massively parallel unbiased sequencing to enable metatranscriptome analysis of complex microbial communities, whole transcriptome and novel transcript identification, as well as RNA-Seq of single eukaryotic cells.

Cell growth – use bioreactors, plant growth chamber and cell culture facility to support the controlled growth of microbial cells, plants or cell lines under defined conditions for further analyses.

Data interpretation – use computational and modeling tools for data intensive omics data analyses, assimilation and visualization, and quantitative image analysis and statistics tools to achieve meaningful conclusions.

Description

Capability Details

Super-resolution fluorescence structured illumination microscopy (SIM) enables 3D imaging of intact hydrated cells with 120 nm lateral resolution. Resolves protein complexes and subcellular structures using any fluorescent protein or dye.

Stochastic optical reconstruction microscopy (STORM), also known as photo-activated localization microscopy (PALM), enables imaging intact hydrated cells with 20-30 nm resolution. Reconstructs super-resolution fluorescence images of protein complexes and subcellular structures in intact hydrated cells with unprecedented resolution.

Combined atomic force microscopy (AFM) and STORM/PALM for 3D mapping of cellular structures with 1-10 nm resolution coupled with single-molecule and super resolution fluorescence imaging to identify distinct proteins and molecular complexes in the membrane of intact cells or organelles.

Multi-photon fluorescence microscopy system that seamlessly integrates nonlinear excitation, laser scanning confocal microscopy, fluorescence lifetime imaging (FLIM) and differential interference contrast (DIC) imaging. Enables minimally invasive and deeply penetrating laser excitation for high-resolution 3D imaging and detection of molecular interactions in single cells, cell communities or tissues.

Time-lapse single molecule fluorescence imaging uses total internal reflection fluorescence (TIRF) techniques to track individual molecules or organelles in live cells. Enables the study of subcellular processes over time and molecular interaction dynamics using fluorescence resonance energy transfer (FRET) in live cells.

Two SOLiD® systems together with the Ion Proton™ provide unbiased global transcriptome analyses with high accuracy and throughput using multiplexing capability for RNA sequencing (RNA-Seq) of multiple samples in parallel. Enables global gene expression analyses, novel gene or isoform identification, and regulation of gene expression studies, such as ChIP-Seq or microRNA analyses in complex microbial communities or individual organisms.

The Influx™ flow cytometer/cell sorter has multiple laser lines and powerful detection capabilities for high throughput analysis and sorting of distinct cells or organelles using advanced multi-parameter sorting technologies based on the presence and content of distinct genes and proteins or intracellular structures. Supports detection and sorting of nanoscale particles, making it highly suited for sorting and analyzing organelles and single cells.

High-resolution laser capture microdissection microscope equipped with a 100x magnification objective lens and multiple fluorescence lines. Enables the enrichment of distinct organelles or isolation of single cells from cell populations or tissue sections for further analyses.

The CyTOF® mass cytometer uses Time-of-Fight mass spectrometry in single cells to quantify the expression of multiple proteins or mRNA species, each tagged with a different stable heavy metal isotope. Enables high throughput single cell analysis of the expression of multiple proteins using antibodies or multiple genes using in situ hybridization probes.

Bioreactors for controlled growth and monitoring of diverse microbial cells in volumes ranging from 100 µl wells to multi-liter reactors. These include the Bioscreen-C™ for automated real-time analysis of growth rate in up to 200 independent 100 µl wells; the Micro-24 MicroReactor system for 24 independently controlled 5 ml reactors; and the BioFlo® 310 benchtop fermentor-bioreactor system for larger volumes.

Instruments

The Influx, a one-of-a kind flow cytometer/cell sorter, provides 5 laser lines simultaneously, powerful detection capabilities and diverse sorting...
Custodian(s): Galya Orr
The JEOL JEM-3000SFF was designed for high-resolution cryogenic transmission electron microscopy (cryo-EM) of biological samples and expands EMSL/...
This time-lapse fluorescence microscope with single molecule detection sensitivity is used to follow individual molecules or organelles in their...
Custodian(s): Galya Orr
This Laser Capture Microdissection system is equipped with 100 x objective lens for enriching distinct organelles, or isolating single cells from...
Custodian(s): Dehong Hu
Two massively parallel next-generation sequencing platforms (SOLiD 5500 series) are currently incorporated in users' research for transcriptomics...
Custodian(s): Galya Orr, Lye Meng Markillie

Publications

Here we describe an ultrasensitive electrochemical nucleic acids assay amplified by carbon nanotubes (CNTs)-based labels for the detection of human...
Removal of highly abundant proteins in plasma is often carried out using immunoaffinity depletion to extend the dynamic range of measurements to...
We recently discovered that MgAl2O4 spinel {111} nano-facets optimally stabilize the small sizes of platinum nanoparticles even after severe high...
Fragmentation of actinyl(VI) complexes UVIO2(L)22+, NpVIO2(L)22+ and PuVIO2(L)22+ (L = tetramethyl-3-oxa-glutaramide, TMOGA) produced by electrospray...
Cerium oxide nanoparticles (CNPs) have gained a considerable attention in biological research due to their anti-oxidant like behaviour and...

Science Highlights

Posted: January 28, 2015
Scientists at Pacific Northwest National Laboratory, University of Puget Sound and EMSL used EMSL resources and capabilities to study the...
Posted: June 17, 2014
The Science Many bacterial species have genes called mraZ and mraW, which are located in a cluster of genes that regulate cell division and cell...
Posted: May 13, 2014
EMSL and Pacific Northwest National Laboratory scientists isolated two bacterial consortia from a microbial mat in Hot Lake, in north-central...
Posted: September 16, 2013
A new transcriptomics-based model accurately predicts how much isoprene the bacterium Bacillus subtilis will produce when stressed or nourished....
Posted: October 28, 2010
Nanoparticles show promise in solving a host of problems, from pinpointing medical diagnoses to developing alternative forms of energy and creating...

The Cell Isolation and Systems Analysis (CISA) capability provides technologies and expertise to study individual cells and cell communities or tissues at the molecular level. Live cells or organelles can be isolated from complex populations, including environmental microbial communities or plant tissues for analyses spanning quantitative live cell fluorescence imaging with single molecule sensitivity, super resolution fluorescence and atomic force microscopy, and transcriptomic analyses using next-generation sequencing technologies.  See a complete list of CISA instruments.

Together with proteomics, metabolomics, and electron and ion microscopy, these capabilities provide the foundation for attaining a molecular-level understanding of individual cells and cell community dynamics and function to support biofuel research, understand the role of biological systems in carbon cycling, and enable research in biodefense and other national needs. 

Resources and Techniques

High-resolution quantitative fluorescence microscopy in living cells – use multi-photon, confocal, single-molecule and super resolution fluorescence microscopy, including STORM/PALM coupled with atomic force microscopy and structured illumination microscopy (SIM), fluorescence resonance energy transfer (FRET) and fluorescence lifetime imaging (FLIM) in intact cells.

Cell and organelle isolation – use the Influx™ flowcytometer cell sorter, and a high-resolution laser capture microdissection microscope for isolating distinct cell populations or single cells and organelles from complex microbial communities or tissues for further analyses.

Transcriptomics – use the SOLiD® 5500 series next-generation sequencing systems together with the Ion Proton™ system for massively parallel unbiased sequencing to enable metatranscriptome analysis of complex microbial communities, whole transcriptome and novel transcript identification, as well as RNA-Seq of single eukaryotic cells.

Cell growth – use bioreactors, plant growth chamber and cell culture facility to support the controlled growth of microbial cells, plants or cell lines under defined conditions for further analyses.

Data interpretation – use computational and modeling tools for data intensive omics data analyses, assimilation and visualization, and quantitative image analysis and statistics tools to achieve meaningful conclusions.

Influence of Adsorption Site and Wavelength on the Photodesorption of NO from the (Fe,Cr)3O4(111) Mixed Oxide Surface.

Abstract: 

The photochemical properties of nitric oxide on a mixed oxide single crystal surface was examined in ultrahigh vacuum (UHV) using temperature programmed desorption (TPD), photon stimulated desorption (PSD) and low energy electron diffraction (LEED). The mixed oxide was a 75% Fe and 25% Cr corundum (0001) oxide film prepared on an -Al2O3(0001) crystal, however its surface became terminated with a magnetite-like (111) structure after sputter/anneal cleaning, leading to a surface designated of (Fe,Cr)3O4(111). TPD of NO from the (Fe,Cr)3O4(111) surface revealed three chemisorbed states at 220, ~315 and 370 K assigned to NO binding at Fe3+, Cr3+ and Fe2+ sites, respectively. No significant thermal chemistry of NO was detected. NO photodesorption, the primary photochemical pathway in UHV, was sensitive to the adsorption site, with rates at the three adsorption sites following the trend: Fe3+ > Fe2+ > Cr3+. Multiexponential rate behavior seen in the overall NO PSD spectra was linked directly to site heterogeneity being manifested as a convolution of the individual NO photodesorption rates at the three types of surface sites. The photodesorption rate with UV light (365 nm) was ~10 times greater than that in the visible, but the per-photon rates across the visible spectrum (from 460 to 630 nm) were independent of the wavelength, which is suggestive of localized photon absorption at the adsorption site. Results in this study demonstrate that the adsorption site plays a critical role in determining photochemical rates on complex oxide surfaces. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multi-program national laboratory operated for DOE by Battelle. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

Citation: 
Henderson MA.2014."Influence of Adsorption Site and Wavelength on the Photodesorption of NO from the (Fe,Cr)3O4(111) Mixed Oxide Surface."Journal of Physical Chemistry C 118(36):21021-21030. doi:10.1021/jp506602x
Authors: 
MA Henderson
Facility: 
Volume: 
118
Issue: 
36
Pages: 
21021-21030
Publication year: 
2014

Diffusional Motion of Redox Centers in Carbonate Electrolytes .

Abstract: 

Ferrocene (Fc) and N-(ferrocenylmethyl)-N,N-dimethyl-N-ethylammonium bistrifluoromethyl-sulfonimide (Fc1N112-TFSI) were dissolved in carbonate solvents and self diffusion coefficents (D) of solutes and solvents were measured by 1H and 19F pulsed field gradient (PFG) nuclear magnetic resonance (NMR) spectroscopy. The organic solvents were propylene carbonate (PC), ethyl methyl carbonate (EMC) and a ternary mixture that also includes ethylene carbonate (EC). Results from NMR studies over the temperature range of 0-50 °C and for various concentrations (0.25 - 1.7 M) of Fc1N112-TFSI are compared to values of D simulated with classical molecular dynamics (MD). The measured self-diffusion coefficients gradually decreased as the Fc1N112-TFSI concentration increased in all solvents. Since the peaks for the two ions (Fc1N212 and TFSI) are separated in one-dimensional NMR spectra, separate diffusion coefficients could be measured and DTFSI is larger than DFc1N112 in all samples measured. The EC, PC and EMC have the same D in the neat solvent mixture and when Fc is dissolved in EC/PC/EMC at a concentration of 0.2 M, probably due to the interactions between common carbonyl structures within EC, PC and EMC. A difference in D (DPC < DEC < DEMC), and both a higher Ea for translational motion and higher effective viscosity for PC in the mixture containing Fc1N112-TFSI reflect the interaction between PC and Fc1N112+, which is a relatively stronger interaction than that between Fc1N112+ and other solvent species. In the EC/PC/EMC solution that is saturated with Fc1N112-TFSI, we find that DPC = DEC = DEMC and Fc1N112+ and all components of the EC/PC/EMC solution have the same Ea for translational motion, while the ratio DEC/PC/EMC/DFc1N112+ is approximately 3. These results reflect the lack of available free volume for independent diffusion in the saturated solution. The Fc1N112+ transference numbers lie around 0.4 and increases slightly as the temperature is increased in the PC and EMC solvents. The trends observed for D from simulations are in good agreement with experimental results and provide molecular level understanding of the solvation structure of Fc1N112-TFSI dissolved in EC/PC/EMC.

Citation: 
Han KS, NN Rajput, X Wei, W Wang, JZ Hu, KA Persson, and KT Mueller.2014."Diffusional Motion of Redox Centers in Carbonate Electrolytes ."Journal of Chemical Physics 141(10):104509. doi:10.1063/1.4894481
Authors: 
KS Han
NN Rajput
X Wei
W Wang
JZ Hu
KA Persson
KT Mueller
Instruments: 
Volume: 
Issue: 
Pages: 
Publication year: 
2014

Low-Temperature Carbon Monoxide Oxidation Catalysed by Regenerable Atomically Dispersed Palladium on Alumina.

Abstract: 

Catalysis by single isolated atoms of precious metals has attracted much recent interest since it promises the ultimate economy in atom efficiency. Previous reports have been confined to reducible oxide supports such as FeOx, TiO2 or CeO2. Here we show that isolated Pd atoms can be stabilized on industrially relevant gamma-alumina supports. At low Pd loadings (≤0.5 wt%) these catalysts contain exclusively atomically dispersed Pd species. The addition of lanthanum-oxide to the alumina, long known for its ability to improve alumina stability, is found to also help in the stabilization of isolated Pd atoms. Aberration-corrected scanning transmission electron microscopy (AC-STEM) confirms the presence of intermingled Pd and La on the gamma-alumina surface. Operando X-ray absorption spectroscopy, performed on Pd/La-alumina and Pd/gamma-alumina (0.5 wt% Pd) demonstrates the presence of catalytically active atomically dispersed ionic Pd in the Pd/La-doped gamma-alumina system. CO oxidation reactivity measurements show onset of catalytic activity at 40 ˚C, indicating that the ionic Pd species are not poisoned by CO. The reaction order in CO and O2 is positive, suggesting a reaction mechanism that is different from that on metallic Pd. The catalyst activity is lost if the Pd species are reduced to their metallic form, but the activity can be regenerated by oxidation at 700 ˚C in air. The high-temperature stability of these ionic Pd species on commercial alumina supports makes this catalyst system of potential interest for low-temperature exhaust treatment catalysts.

Citation: 
Peterson E, A DelaRiva, S Lin, RS Johnson, H Guo, J Miller, JH Kwak, CHF Peden, B Kiefer, LF Allard, F Ribeiro, and AK Datye.2014."Low-Temperature Carbon Monoxide Oxidation Catalysed by Regenerable Atomically Dispersed Palladium on Alumina."Nature Communications 5:Article No. 4885. doi:10.1038/ncomms5885
Authors: 
E Peterson
A DelaRiva
S Lin
RS Johnson
H Guo
J Miller
JH Kwak
CHF Peden
B Kiefer
LF Allard
F Ribeiro
AK Datye
Volume: 
Issue: 
Pages: 
Publication year: 
2014

Polysialylated N-Glycans Identified in Human Serum Through Combined Developments in Sample Preparation, Separations and

Abstract: 

The N-glycan diversity of human serum glycoproteins, i.e. the human blood serum N-glycome, is complex due to the range of glycan structures potentially synthesizable by human glycosylation enzymes. The reported glycome, however, is limited by methods of sample preparation, available analytical platforms, e.g., based upon electrospray ionization-mass spectrometry (ESI-MS), and software tools for data analysis. In this report, several improvements have been implemented in sample preparation and analysis to extend ESI-MS glycan characterization and to provide an improved view of glycan diversity. Sample preparation improvements include acidified, microwave-accelerated, PNGase F N-glycan release, and sodium borohydride reduction were optimized to improve quantitative yields and conserve the number of glycoforms detected. Two-stage desalting (during solid phase extraction and on the analytical column) increased the sensitivity by reducing analyte signal division between multiple reducing-end-forms or cation adducts. On-line separations were improved by using extended length graphitized carbon columns and adding TFA as an acid modifier to a formic acid/reversed phase gradient which provides additional resolving power and significantly improved desorption of both large and heavily sialylated glycans. To improve MS sensitivity and provide gentler ionization conditions at the source-MS interface, subambient pressure ionization with nanoelectrospray (SPIN) has been utilized. When method improvements are combined together with the Glycomics Quintavariate Informed Quantification (GlyQ-IQ) recently described1 these technologies demonstrate the ability to significantly extend glycan detection sensitivity and provide expanded glycan coverage. We demonstrate application of these advances in the context of the human serum glycome, and for which our initial observations include detection of a new class of heavily sialylated N-glycans, including polysialylated N-glycans.

Citation: 
Kronewitter SR, I Marginean, JT Cox, R Zhao, CD Hagler, AK Shukla, TS Carlson, JN Adkins, DG Camp, II, RJ Moore, KD Rodland, and RD Smith.2014."Polysialylated N-Glycans Identified in Human Serum Through Combined Developments in Sample Preparation, Separations and Electrospray ionization-mass spectrometry."Analytical Chemistry 86(17):8700-10. doi:10.1021/ac501839b
Authors: 
SR Kronewitter
I Marginean
JT Cox
R Zhao
CD Hagler
AK Shukla
TS Carlson
JN Adkins
DG Camp
II
RJ Moore
KD Rodl
RD Smith
Facility: 
Instruments: 
Volume: 
86
Issue: 
17
Pages: 
8700-10
Publication year: 
2014

Composition and Interface Analysis of InGaN/GaN Multiquantum-Wells on GaN Substrates Using Atom Probe Tomography.

Abstract: 

In0.20Ga0.80N/GaN multi-quantum wells grown on [0001]-oriented GaN substrates with and without an InGaN buffer layer were characterized using three-dimensional atom probe tomography. In all samples, the upper interfaces of the QWs were slightly more diffuse than the lower interfaces. The buffer layers did not affect the roughness of the interfaces within the quantum well structure, a result attributed to planarization of the surface of the 1st GaN barrier layer which had an average root-mean-square roughness of 0.177 nm. The In and Ga distributions within the MQWs followed the expected distributions for a random alloy with no indications of In clustering.

Citation: 
Liu F, L Huang, RF Davis, LM Porter, DK Schreiber, SVNT Kuchibhatla, V Shutthanandan, S Thevuthasan, E Preble, T Paskova, and KR Evans.2014."Composition and Interface Analysis of InGaN/GaN Multiquantum-Wells on GaN Substrates Using Atom Probe Tomography."Journal of Vacuum Science and Technology B--Microelectronics and Nanometer Structures 32(5):Article No. 051209. doi:10.1116/1.4893976
Authors: 
F Liu
L Huang
RF Davis
LM Porter
DK Schreiber
SVNT Kuchibhatla
V Shutthanan
S Thevuthasan
E Preble
T Paskova
KR Evans
Volume: 
Issue: 
Pages: 
Publication year: 
2014

Symmetries of migration related segments of all [001] coincidence site lattice tilt boundaries in (001) projections for all

Abstract: 

Utilizing bicrystallography in two dimensions (2D), the symmetries of migration related segments of Coincidence Site Lattice (CSL) boundaries are derived for projections along their [001] tilt axis in grain boundaries of crystalline materials that possess the holohedral point symmetry of the cubic system (i.e. m3m). These kinds of “edge-on” projections are typical for atomic resolution imaging of such tilt boundaries with Transmission Electron Microscopes (TEM). This fact facilitates the visual confirmation of our predictions by recently published Zcontrast scanning TEM investigations [H. Yang et al., Phil. Mag. 93 (2013) 1219] and many other TEM studies.

Citation: 
Moeck P, BW York, and ND Browning.2014."Symmetries of migration related segments of all [001] coincidence site lattice tilt boundaries in (001) projections for all holohedral cubic materials."Crystal Research & Technology 49(9):708-720. doi:10.1002/crat.201400071
Authors: 
P Moeck
BW York
ND Browning
Instruments: 
Volume: 
49
Issue: 
9
Pages: 
708-720
Publication year: 
2014

Behavior of nanoceria in biologically-relevant environments.

Abstract: 

Cerium oxide nanoparticles (CNPs) have gained a considerable attention in biological research due to their anti-oxidant like behaviour and regenerative nature. The current literature on CNPs reports many successful attempts on harnessing the beneficial therapeutic properties in biology. However studies have also shown toxicity effect with some types of CNPs. This review discusses issues associated with the behaviours of CNPs in biological systems and identifies key knowledge gaps. We explore how salient physicochemical properties (size, surface chemistry, surface stabilizers) contribute to the potential positive and negative aspects of nanoceria in biological systems. Based on variations of results reported in the literature, important issues need to be addressed. Are we really studying the same particles with slight variations in size and physicochemical properties or do the particles being examined have fundamentally different behaviours? Are the variations observed in the result of differences in the initial properties of the particles or the results of downstream effects that emerge as the particles are prepared for specific studies and they interact with biological or other environmental moieties? How should particles be appropriately prepared for relevant environmental/toxicology/safety studies? It is useful to recognize that nanoparticles encompass some of the same complexities and variability associated with biological components

Citation: 
Kumar A, S Das, P Munusamy, W Self, DR Baer, DC Sayle, and S Seal.2014."Behavior of nanoceria in biologically-relevant environments."Environmental Science: Nano 1(6):516-532. doi:10.1039/C4EN00052H
Authors: 
A Kumar
S Das
P Munusamy
W Self
DR Baer
DC Sayle
S Seal
Instruments: 
Volume: 
1
Issue: 
6
Pages: 
516-532
Publication year: 
2014

Experimental and Theoretical Studies on the Fragmentation of Gas-Phase Uranyl-, Neptunyl- and Plutonyl-Diglycolamide Complexes.

Abstract: 

Fragmentation of actinyl(VI) complexes UVIO2(L)22+, NpVIO2(L)22+ and PuVIO2(L)22+ (L = tetramethyl-3-oxa-glutaramide, TMOGA) produced by electrospray ionization was examined in the gas phase by collision induced dissociation (CID) in a quadrupole ion trap mass spectrometer. Cleavage of the C-Oether bond was observed for all three complexes, with dominant products being UVIO2(L)(L-86)+ with charge reduction, and NpVIO2(L)(L-101)2+ and PuVIO2(L)(L-101)2+ with charge conservation. The neptunyl and plutonyl complexes also exhibited substantial L+ loss to give pentavalent complexes NpVO2(L)+ and PuVO2(L)+, whereas the uranyl complex did not, consistent with the comparative An 5f-orbital energies and the AnVIO22+/AnVO2+ (An = U, Np, Pu) reduction potentials. CID of NpVO2(L)2+ and PuVO2(L)2+ was dominated by neutral ligand loss to form NpVO2(L)+ and PuVO2(L)+, which hydrated by addition of residual water in the ion trap; UVO2(L)2+ was not observed. Theoretical calculations of the structures and bonding of the AnVIO2(L)22+ complexes using density functional theory reveal that the metal centers are coordinated by six oxygen atoms from the two TMOGA ligands. The results are compared with radiolytic decomposition of TMOGA in solution.

Citation: 
Gong Y, HS Hu, L Rao, J Li, and JK Gibson.2013."Experimental and Theoretical Studies on the Fragmentation of Gas-Phase Uranyl-, Neptunyl- and Plutonyl-Diglycolamide Complexes."Journal of Physical Chemistry A 117(40):10544-10550. doi:10.1021/jp4076977
Authors: 
Y Gong
HS Hu
L Rao
J Li
JK Gibson
Instruments: 
Volume: 
117
Issue: 
40
Pages: 
10544-10550
Publication year: 
2013

A general mechanism for stabilizing the small sizes of precious metal nanoparticles on oxide supports.

Abstract: 

We recently discovered that MgAl2O4 spinel {111} nano-facets optimally stabilize the small sizes of platinum nanoparticles even after severe high temperature aging treatments. Here we report the thermal stabilities of other precious metals with various physical and chemical properties on the MgAl2O4 spinel {111} facets, providing important new insights into the stabilization mechanisms. Besides Pt, Rh and Ir can also be successfully stabilized as small (1-3 nm) nanoparticles and even as single atomic species after extremely severe (800 °C, 1 week) oxidative aging. However, other metals either aggregate (Ru, Pd, Ag, and Au) or sublimate (Os) even during initial catalyst synthesis. On the basis of ab initio theoretical calculations and experimental observations, we rationalize that the exceptional stabilization originates from lattice matching, and the correspondingly strong attractive interactions at interfaces between the spinel {111} surface oxygens and epitaxial metals\metal oxides. On this basis, design principles for catalyst support oxide materials that are capable in stabilizing precious metals are proposed.

Citation: 
Li WZ, L Kovarik, D Mei, MH Engelhard, F Gao, J Liu, Y Wang, and CHF Peden.2014."A general mechanism for stabilizing the small sizes of precious metal nanoparticles on oxide supports."Chemistry of Materials 26(19):5475-5481. doi:10.1021/cm5013203
Authors: 
Li WZ
L Kovarik
D Mei
MH Engelhard
F Gao
J Liu
Y Wang
CHF Peden
Volume: 
26
Issue: 
19
Pages: 
5475-5481
Publication year: 
2014

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