SUPPLEMENTARY INFORMATION...immersed in an oil bath between 20 and 130 °C (see Table S2). The...

1

Supplementary Information

A silica sol-gel design strategy for nanostructured metallic materials

Scott C Warren124 Matthew R Perkins1 Ashley M Adams2 Marleen Kamperman1

Andrew A Burns1 Hitesh Arora13 Erik Herz1 Teeraporn Suteewong1 Hiroaki Sai1

Zihui Li12 Joumlrg Werner12 Juho Song13 Ulrike Werner-Zwanziger5 Josef W

Zwanziger5 Michael Graumltzel4 Francis J DiSalvo2 amp Ulrich Wiesner1

1Department of Materials Science amp Engineering Cornell University Ithaca NY

14853 USA 2Department of Chemistry amp Chemical Biology Cornell University

Ithaca NY 14853 USA 3School of Chemical and Biomolecular Engineering 4Laboratory of Photonics and Interfaces Ecole Polytechnique Feacutedeacuterale de Lausanne

Lausanne Switzerland 5Chemistry Department Dalhousie University Halifax Nova

Scotia Canada B3H 4R2

Equipment

Standard Schlenk line techniques were used for the synthesis of the sol-gel

precursor All components of the sol-gel precursor were synthesized and handled under

nitrogen except for the first step of the protocol for hydroxy acids which could be

performed in air We did not determine whether such rigorous handling procedures

were necessary to prevent hydrolysis of the silicon alkoxide NMR spectra were

acquired on a Varian Inova at 400 MHz (1H) and 100 MHz (13C) Assignment of peaks

SUPPLEMENTARY INFORMATIONDOI 101038NMAT3274

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copy 2012 Macmillan Publishers Limited All rights reserved

2

in the NMR spectra was assisted by ChemDraw Ultra SEM imaging of Pd-C-silica

nanocomposites was performed using a FEI XLF30-SFEG operated at 10 kV and EDX

was performed at 20 kV SEM imaging of the nanocomposite templated by beads was

performed using a Leo 1550 FE-SEM at 10 kV TEM was performed using a

PhillipsFEI CM300 operated at 300 kV Powder x-ray diffraction (PXRD) was

performed using a Bruker AXS with a Lynxeye detector Van der Pauw electrical

conductivity measurements were performed with a Keithley 2400 source meter Prior to

electrical measurement samples were dipped in aqua regia for 5 seconds rinsed in

water and dried to eliminate a palladium-rich surface phase Electrical contacts to the

sample were made using low melting point Cerasolzer In Fig S1 we show an

experimental setup for a pyrolyzed Pd-C-SiO2 film in the Van der Pauw geometry

Figure S1 | Experimental geometry for Van der Pauw conductivity

measurements

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SUPPLEMENTARY INFORMATION DOI 101038NMAT3274


3

Chemicals

All chemicals were used as received except as noted below 3-

isocyanatopropyltriethoxysilane (Sigma Aldrich 95) was distilled under high vacuum

prior to use discarding the first and last fractions Metal acetates that were sold as

hydrates were evacuated several hours at high vacuum to dry the compound

Anhydrous DMF (998) was purchased from Sigma Aldrich and Alfa Aesar

Carboxylic acids were purchased from Sigma Aldrich or Alfa Aesar and were of the

highest purity available (typically 99) Diprotin A and the methyl ester of aspartic

acid were purchased from BaChem Metal acetates were purchased from a variety of

sources including Sigma Aldrich Alfa Aesar DFG Goldsmith and Gelest THF was

distilled first from sodium and then from n-butyl lithiumdiphenylethylene

Poly(isoprene-block-ethylene oxide) was synthesized using anionic polymerization For

the Stoumlber particle synthesis ethanol and ammonia in ethanol (2 M) were purchased

from Pharmco and Aldrich respectively TEOS was purchased from Gelest

Platinum acetate

The only metal acetate that we synthesized was platinum acetate While City

Chemical claims to sell platinum acetate we identified the material as silver acetate

Platinum acetate is a brown-black powder[1] they sold us a colorless compound

The synthesis of platinum acetate (Pt4ac8)[1] follows a patent[2] in which PtCl4

and silver acetate are combined in a 15 molar ratio and refluxed in acetic acid until the

yellow color is entirely replaced by a black color (about 2 hours) The reaction is

performed in air In a typical synthesis 043 g of PtCl4 107 g of silver acetate and 25

mL of acetic acid were combined and refluxed After cooling to room temperature the




4

silver chloride byproduct (confirmed by PXRD) was removed via filtration through

Whatman filter paper The silver chloride was rinsed with chloroform to extract as

much product as possible The black solution was rotary evaporated and exposed to

high vacuum for several hours to fully remove acetic acid The product was dissolved

in 25 mL of CH2Cl2 and filtered through Whatman filter paper The CH2Cl2 was

removed by rotary evaporation to yield a brown-black powder yield = 66 See Fig

S2 for the NMR spectrum Ligand exchange reactions on Pt4ac8 proceed at room

temperature and replace only the four in-plane ligands[3]

Figure S2 | 1H NMR of Pt4(ac)8

Summary of synthesized sol-gel precursors

The precursors that have been successfully synthesized are listed in Table S1




5

Table S1 | Sol-gel precursors that were synthesized Carboxylic acid Metals Comments

L-(+)-isoleucine

Ag (Ag2tfa2) Bi Co Cr Cu Er Eu Gd In Mg Mn Ni Pb Pd Pt (Pt4ac8) Sr Y Zn

Exhibits high solubility Product is glassy or is extremely viscous Used silver trifluoroacetate instead of silver acetate as silver source

-amino butyric acid Mo (Mo2ac4) Rh (Rh2ac4)

Dimeric metal acetates need less sterically demanding ligands to ensure complete ligand exchange

DL-2-aminobutyric acid Cu Gd L-(+)-phenylalanine Zn L-(+)--phenylglycine Zn 6-aminohexanoic acid Pb Exhibits low solubility L-valine Cu Zn DL--leucine Cu Diprotin A (Ile-Pro-Ile) Gd L-(+)-lactic acid Cu Zn 2-hydroxy-3-methylbutyric acid Co Cu Zn (R)-2-hydroxybutyric acid Zn (S)-2-hydroxybutyric acid Zn 22-dimethyl-3-hydroxypropionic acid Mo (Mo2ac4) Zn Product is Mo2ac1BMS3 as

determined by NMR L-(+)-mandelic acid Cu Zn 1-methyl-L-aspartic acid Co Pd Cu

Ligand exchange reactions

The ligand exchange on the metal acetate to liberate acetic acid was conducted

under dynamic vacuum at varying temperatures More labile acetates could be

exchanged at lower temperatures (eg at 20 degC) while less labile acetates required

higher temperatures (temperatures up to 150 degC) as described in Table S2 The

distillate temperature was typically ~40 degC lower than the oil bath temperature The

following table lists the oil bath temperatures employed For the higher temperatures




6

care was taken to increase the distillation pressure (that is closer to atmospheric

pressure) to prevent the premature distillation of the DMF prior to ligand exchange

Table S2 | Ligand exchange temperature Oil bath temperature Metal acetate

20 degC Pt

50 degC Ag

70 degC Cu Mo Pd Rh

90 degC Co Er Eu Fe Gd Mn Zn

110 degC Bi Cr Ni Pb Y

130 degC In Mg

150 degC Sr

The ligand exchange and DMF distillation were performed using a short path

distillation head with vacuum tubing connecting the distillation head to a

vacuumnitrogen port of a vacuum line The acetic acid and DMF were typically

collected in a flask cooled by liquid nitrogen to prevent the distillate from entering into

the vacuum line

The reaction progress could be gauged by the disappearance of the metal acetate

(a solid) which typically had low solubility in DMF Once the reaction reached an

appropriate temperature for ligand exchange the reaction was typically complete in a

few minutes After distillation the flask containing the sol-gel precursor was connected

directly to the vacuum line until the pressure stabilized at 10-2 mbar to complete the

removal of all volatile components This typically required a few hours




7

Syntheses of amino acid-based sol-gel precursors

In a typical synthesis we combined 005 mol of L-isoleucine (656 g) and 005

mol of 3-isocyanatopropyltriethoxysilane (ICPTS) (1237 g) with 700 mL of anhydrous

DMF in a 1-L flask The reaction was stirred in an oil bath at 80 degC for 12 hours under

nitrogen After cooling to room temperature we removed unreacted L-isoleucine by

pouring the reaction contents through dry Whatman filter paper Typically 23 of the

L-isoleucine had not reacted At this point the L-isoleucine-ICPTS complex could be

isolated by distilling the DMF at reduced pressure to afford a colorless transparent and

viscous liquid However for most syntheses we added the metal acetate directly to the

DMF solution An amount of metal acetate ([005 mol(1-023)]n where n is the

oxidation state of the metal) was added to permit complete replacement of the L-

isoleucine-ICPTS complex for the acetate (the formula takes the amount of amino acid

multiplies it by the yield and divides it by the metal oxidation state) The solution was

heated again gradually increasing the temperature to 20-130 degC (depending on the

metal) while applying dynamic vacuum to distil the acetic acid and DMF The products

were clear viscous liquids or glassy solids that had the same color as the starting metal

acetate The products readily dissolved in a wide range of solvents although some

reacted with chloroform and all underwent alcoholysis or hydrolysis NMR was

typically performed in anhydrous DMSO-d6

In later experiments we found that the reaction also proceeds efficiently under

less rigorous conditions The following changes did not appear to have a significant

detrimental impact on the precursor synthesis (1) use of unpurified ICPTS instead of

distilled ICPTS (2) reaction under atmospheric conditions instead of an inert

atmosphere (3) and the removal of the excess DMF on a rotary evaporator as opposed

to a distillation head connected to a Schlenk line




8

Syntheses of hydroxyl acid-based sol-gel precursors

We combined 005 mol of a metal acetate eg Cu(II) acetate and 010 mol of a

hydroxy acid eg 2-hydroxy-3-methyl-butanoic acid 50 mL of DMF was added and

vacuum was applied immediately to the solution and the flask was simultaneously

immersed in an oil bath between 20 and 130 degC (see Table S2) The solution bubbled

vigorously for a few minutes as acetic acid was evolved and DMF was then distilled as

the solution warmed This afforded 005 mol of a metal hydroxo acetate To ensure the

product was anhydrous vacuum was applied to the powder for several hours Next the

metal hydroxo acetate was dissolved in 100 mL of anhydrous DMF and 010 mol of

ICPTS was added Stirring the solution at room temperature overnight and vacuum

distillation of the DMF afforded the title compound in quantitative yield

Syntheses of peptide-based sol-gel precursors

Equimolar amounts of ICPTS and the peptide were combined For example

015 mmol of ICPTS and 015 mmol of diprotin A (a peptide with an Ile-Pro-Ile

sequence) were combined in 35 mL of anhydrous DMF Subsequent addition of an

amount of metal acetate ([015(1-015)]n mol where n is the oxidation state of the

metal and assuming an 85 yield) was added and subsequent distillation of the acetic

acid and DMF under high vacuum at 50 degC afforded the viscous product

1H and 13C NMR spectra of sol-gel precursors

The following series of NMR spectra (Fig S3-S5) show each step in the synthesis

of a zinc-lactic acid sol-gel precursor Only the expected peaks for the product are

observed In particular the 13C spectrum shows the presence of only two types of

carbonyl carbonsmdashthe carboxylate and the urethane These features demonstrate that




9

the carboxylate ligates exclusively to the zinc and that the isocyanate reacts

quantitatively to form the urea confirming the high purity of the product

Figure S3 | 1H NMR of L-(+)-lactic acid in d6-DMSO ()

Figure S4 | 1H NMR of zinc L-(+)-lactate in d6-DMSO ()




10

Figure S5 | 1H NMR of an ICPTS-lactate-zinc sol-gel precursor in d6-DMSO ()

The following series of NMR (Fig S6-S9) show a diprotin A-based sol-gel

precursor and the coordination of the ligand to gadolinium Upon coordination to Gd

the proton relaxivity is strongly enhanced as suggested by the broadened peaks in both

the 1H (Fig S7) and 13C NMR (Fig S9) spectra Additionally the signal from the

carboxylic acid proton is enhanced (Fig S7 124 ppm) Here an ~18 excess of the

ICPTS-diprotin A ligand was employed in the ligand exchange with gadolinium acetate

to ensure complete ligand exchange The signal from the protons of the unreacted

carboxylic acid may be disproportionately enhanced due to the presence of the Gd




11

Figure S6 | 1H NMR of an ICPTS-diprotin A ligand in d6-DMSO ()

Figure S7 | 1H NMR of an ICPTS-diprotin A-Gd sol-gel precursor in d6-DMSO




12

Figure S8 | 13C NMR of an ICPTS-diprotin A ligand in d6-DMSO ()

Figure S9 | 13C NMR of an ICPTS-diprotin A-Gd sol-gel precursor in d6-DMSO ()

The DMSO peak is truncated

The following series of 1H NMR spectra (Fig S10-S12) provide evidence for the

formation of the two most important sol-gel compounds the L-isoleucine-based sol-gel

precursor (which was used to make the films shown in Figure 1) and the 1-methyl-L-




13

aspartic acid precursor which was used to synthesize many of the block copolymer

hybrids because of its increased hydrophilicity For reference the starting molecule 3-

isocyanatopropyl triethoxysilane (ICPTS) is presented first (Fig S10) The peak

labelled (E) is located at 330 ppm and its shift in subsequent spectra (Fig S11 and S12)

is indicative of a reaction between ICPTS and the amino acid

Figure S10 | 1H NMR of ICPTS in CDCl3

The reaction of L-isoleucine with ICPTS is postulated to form the complex

drawn in Figure S11 The spectrum provides the following evidence for the reaction

First the peak labelled (E) shifts to approximately 31 ppm (no peak is observed at 330

ppm) Second the hydrogens labelled (F) and (G) appear within the expected range for

a urea Third the integrated areas of the peaks correspond very well with those

predicted from ChemDraw and therefore suggest that the product has formed in a high

yield




14

Figure S11 | 1H NMR of ICPTS-L-isoleucine in CDCl3 The peak for DMF is

truncated and the spinning side bands are marked with blue Xs

The reaction of 1-methl-L-aspartic acid with ICPTS has the targeted product

illustrated in Figure S12 Again evidence for the formation of the product is seen in

peak (E) which has a chemical shift of 318 ppm and appears as a well-defined

doublet of triplets Peaks (F) and (G) indicate the formation of the urea linkage In this

spectrum there is the additional appearance of ethanol One possible side reaction is

the reversible association of the carboxylic acid with the silicon which liberates

ethanol Bfree and Afree show the presence of that ethanol with the BBfree ratio at close

to 21 as expected from a stoichiometry displacement reaction The ability to

subsequently add insoluble metal acetates to this complex to form a soluble product

along with the production of near-stoichiometric amounts of acetic acid demonstrate

that the association of the carboxylic acid with the silicon is reversible




15

Figure S12 | 1H NMR of ICPTS-1-methyl-L-aspartic acid in CDCl3 The peak for

DMF is truncated and the spinning side bands are marked with blue and magenta Xs

Afree and Bfree indicate ethanol

Reaction of ICPTS with DL--leucine is expected to produce the product drawn

in Figure S13 The urea hydrogens (F) and (G) indicate formation of the product

Figure S13 | 1H NMR of ICPTS-DL--leucine in CDCl3

Reaction of mandelic acid with zinc acetate in a 21 molar ratio followed by

reaction with ICPTS produces is expected to form the product illustrated in Figure S14




16

Figure S14 | 1H NMR of Zn-mandelate-ICPTS in CDCl3

Synthesis of thick sol-gel hybrid films

Typically 03 g of the sol-gel precursor was dissolved in 2 g of anhydrous THF After

stirring for a few minutes to ensure complete dissolution pH 9 H2O (10-5 M NaOH) was

added to initiate hydrolysis and condensation A 11 molar ratio between alkoxide and

water was employed After stirring 10 minutes the film was cast at 50 degC in an

aluminum dish A solid transparent film was produced after 30 minutes of heating

although heating could be continued to increase crosslinking The metal-carboxylic

acid linkage in the sol-gel precursor is air or water sensitive in some cases For water

sensitive complexes such as bismuth the precursor was dissolved in anhydrous THF

and stirred in air for an hour prior to casting the film Because THF is hygroscopic a

small amount of water was delivered to the ligand and allowed the sol-gel process to

occur without extensively hydrolyzing the bismuth For air sensitive complexes such as

molybdenum the entire operation was performed under nitrogen




17

29Si NMR of a hydrolysed and condensed sol-gel film

To confirm that silicon alkoxides hydrolysed and condensed to form Si-O-Si

bonds we performed 29Si magic angle spinning solid state NMR The 29Si experiments

were performed on a Bruker Avance DSX NMR spectrometer with a 94T magnet (400

MHz proton Larmor frequency 7952 MHz 29Si Larmor frequency) using an H-FC-P

probe head For the 29Si experiments the chemical shift scale was referenced against

the center of gravity of the 29Si NMR resonance of Kaolin (CAS 1332-58-7) at -913

ppm Kaolin was also used to set the pulse length cross-polarization conditions and

decoupling pulse length for the 29Si-NMR experiments Proton relaxation times for the

sample were measured by T1-inversion recovery sequence to determine the repetition

time (35s) for the 29Si CPMAS experiments A cross-polarization sequence with

linearly ramped proton power during a 5ms contact pulse and TPPM proton decoupling

was used To determine quantitative compositions a spectrum was acquired with single

pulse excitation (SPE) and TPPM proton decoupling The relaxation time again was

measured using a T1-inversion recovery sequence (following a CP excitation) From

this repetition times of 315seconds were determined to be necessary 512 and 160 scans

were accumulated for the 29Si CPMAS and 29Si SPEMAS NMR spectra respectively

For both spectra the sample was spun at 50 kHz sufficient to show no spinning

sidebands

Fig S15 shows the 29Si CPMAS NMR spectrum of a hydrolysed and condensed

Pd-L-isoleucine-ICPTS sol-gel thick film T1 T2 and T3 resonances are visible

deconvolution of these peaks gives relative areas of 395 548 and 57

respectively which is identical to the SPE spectrum within noise level A peak

(accounting for 2 of the total area) was observed at a resonance of 18 ppm in the




18

single pulse excitation spectrum but was absent in the cross-polarized spectrum this is

consistent with a liquid-like Si species that is entrapped within the film From these

results it is clear that hydrolysis and condensation proceeds as expected to form Si-O-Si

bonds in the vast majority of silicon alkoxides

Figure S15 | 29Si CPMAS solid state NMR spectrum of a L-isoleucine-ICPTS-

palladium hydrolyzed and condensed sol-gel thick film

Synthesis of polystyrene bead arrays and templated porous Pd-silica-carbon

nanocomposite

Polystyrene (PS) beads were used as received 04 mL of a 5 wt suspension

of 600 nm crosslinked PS beads was added to 6 mL of deionized water The diluted

suspension was placed in a 20 mL scintillation vial and sonicated for 30 sec to ensure

dispersion of the beads Glass substrates were cleaned with ethanol and dried under a

nitrogen flow Substrates were dipped vertically into the suspension and were left

overnight at 60 degC until the water evaporated

The interstitial pore space was filled by placing a drop of a partially hydrolysed

palladium-L-isoleucine-ICPTS sol-gel precursor in THF at one side of the bead array

The partially hydrolysed solution was prepared in the same way as described for the




19

thick films After solvent evaporation the sample was heat treated under argon up to

550 ordmC for 5 hours using a 1 ordmC min-1 ramp

Synthesis of Stoumlber-type particles

In a typical synthesis 28 mg of ICPTS-diprotin A-Gd and 11 mL of TEOS was

dissolved in 73 mL of ethanol under nitrogen This was added to a solution of

ammonia water and ethanol that had concentrations of ammonia water and TEOS of

04 324 and 005 M Next for the shell growth TEOS was added gradually in small

aliquots to prevent secondary nucleation using an Eppendorf EDOS dosing system The

total TEOS concentration for the shell growth was 012 M with respect to the original

reaction volume All syntheses were carried out at room temperature

Synthesis of block copolymer hybrids

To synthesize a lamellarinverse hexagonal sol-gel hybrid 0067g016 g of a

ICPTS-1-methyl-L-aspartate-Pd sol-gel precursor was added to 0067 g of a

poly(isoprene-block-ethylene oxide) (PI-b-PEO) block copolymer with a molecular

weight of 125 kgmol and a PEO content of 204 wt (PDI = 110) 2 g of anhydrous

THF was added to dissolve the precursor and polymer The solution was stirred 10

minutes before the addition of 0008 g pH 9 H2O (adjusted with NaOH) After addition

of water the solutions were stirred 30 minutes and then cast in an aluminum dish at 50

degC covered by a hemispherical glass dish to slow the THF evaporation The resulting

films were homogeneous To analyse the mesostructure of these films they were

cryoultramicrotomed and placed onto a copper TEM sample holder




20

Pyrolysis EDX and Raman analysis

Samples were pyrolyzed under flowing N2 or Ar gas using a ramp rate of 2

degCmin and holding at 550 to 700 degC for 2 hours before shutting off the furnace

TEM was used to analyse micron-sized regions of the sample TEM analysis of

a pyrolyzed sample from a hydrolysed and condensed film of the ICPTS-L-isoleucine-

Pd precursor is shown in Fig S16a TEM analysis of a pyrolyzed sample from a

hydrolysed and condensed film of the ICPTS-L-isoleucine-Pd and palladium (II)

methoxyethoxyacetate is shown in Fig S16b These TEM images present larger regions

of samples than are shown in Fig 3 The uniformity of nanoparticle size and the

homogeneity of the nanoparticle spatial distribution are apparent in these images

Samples were broken and cross sections of the film were analysed by EDX

spectroscopy in 5 to 10 places across the film in at least two different regions EDX

spectroscopy was also performed on the top and bottom surfaces of the film The

results of these analyses are incorporated into the average value and standard deviation

of the Pd volume fraction that is reported in Fig 4a An example of a typical analysis is

shown in Fig S16c

Figure S16 | Analysis of homogeneity Pd-SiO2-C porous nanocomposite with a Pd

volume fraction of (a) 21 and (b) 23 (c) Cross sectional SEM image of a Pd-C-

SiO2 film with composition reported in weight-percent at six positions across the cross




21

section as determined by EDX spectroscopy The sample has a Pd volume fraction of

327

Because it is possible that the carbon contributes to the electrical conductivity in

the pyrolyzed samples it was important to assess the crystallinity of the carbonaceous

phase To assess the crystallinity we examined two pyrolyzed samples and one air-

calcined sample by Raman spectroscopy A Ranishaw InVia Raman microscope was

used to collect 90 1-second exposures at 10 intensity at a wavelength of 785 nm The

two pyrolyzed samples differed in that they were pyrolized at either 500 degC or 700 degC

for 5 hours The Raman spectra (Fig S17) indicate that the crystallinity of the

carbonaceous phase is quite poor because the D and G bands (located at 1350 and 1600

cm-1) are very poorly resolved Therefore the contribution of the carbonaceous phase

in providing high electrical conductivity can be neglected

Figure S17 | Raman analysis of pyrolyzed and calcined Pd-based materials

Nitrogen physisorption

Nitrogen physisorption was performed at liquid nitrogen temperatures using an

ASAP 2010 and an ASAP 2020 from Micromeritics From the isotherms we

determined the BET surface area BJH pore size distribution (Fig S18) and total pore




22

volume fraction The total pore volume fraction was estimated as the total nitrogen

uptake at a nitrogen pressure (PP0) of 098 The nitrogen volume fraction was used in

the calculation of the palladium volume fraction

Table S3 | Results of nitrogen physisorption for pyrolyzed and etched Pd-based

samples

Sample Porosity (cm3 pores cm3 sample) BET surface area (m2g) Pd-C-SiO2 (33 vol Pd) 14 51 Pd-C (approx 33 vol Pd) 37 108 Pd-SiO2 (approx 33 vol Pd) 31 62 Pd (approx 33 vol Pd) 52 69 Pd-SiO2 self-assembled from PI-b-PEO block copolymer

53 64

Figure S18 | BJH pore size distributions for the samples listed in Table 1




23

Powder x-ray diffraction

Table S4 tabulates the Scherer domain size of palladium peaks in all samples

At low metal loadings the Pd domain size in each direction is similar At higher

loadings the (111) domain grows One possible interpretation which is consistent

with a lowered threshold for percolation is the formation of anisotropic Pd

nanoparticles that are elongated along one [111] axis The TEM image in Fig S19

shows a nanocomposite at the percolation threshold Some nanoparticles with low

symmetry shapes are visible

Table S4 | Domain sizes for Pd-C-SiO2 porous nanocomposites

Pd vol (111) domain size (nm) (200) domain size (nm) (220) domain size (nm) 225 28 23 30 226 52 36 44 230 55 37 44 236 66 48 48 29 83 59 64 33 97 71 80

346 97 68 74




24

Figure S19 | High resolution TEM image of a porous Pd-C-SiO2 nanocomposite

with a Pd volume fraction of 33

References [1] M A A F d C T Carrondo A C Skapski J Chem Soc Chem Comm

1976 410 [2] D Wright Vol GB1214552 ICI Ltd England 1970 [3] T Yamaguchi Y Sasaki A Nagasawa T Ito N Koga K Morokuma

Inorganic Chemistry 1989 28 4312




2

in the NMR spectra was assisted by ChemDraw Ultra SEM imaging of Pd-C-silica

nanocomposites was performed using a FEI XLF30-SFEG operated at 10 kV and EDX

was performed at 20 kV SEM imaging of the nanocomposite templated by beads was

performed using a Leo 1550 FE-SEM at 10 kV TEM was performed using a

PhillipsFEI CM300 operated at 300 kV Powder x-ray diffraction (PXRD) was

performed using a Bruker AXS with a Lynxeye detector Van der Pauw electrical

conductivity measurements were performed with a Keithley 2400 source meter Prior to

electrical measurement samples were dipped in aqua regia for 5 seconds rinsed in

water and dried to eliminate a palladium-rich surface phase Electrical contacts to the

sample were made using low melting point Cerasolzer In Fig S1 we show an

experimental setup for a pyrolyzed Pd-C-SiO2 film in the Van der Pauw geometry

Figure S1 | Experimental geometry for Van der Pauw conductivity

measurements




3

Chemicals














Platinum acetate












4















5


L-(+)-isoleucine

















6




20 degC Pt

50 degC Ag

70 degC Cu Mo Pd Rh



130 degC In Mg

150 degC Sr





the vacuum line










7





























8



























9








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11






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13













yield




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15












16


















17



















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20
















shown in Fig S16c







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samples


53 64





23











346 97 68 74




24









3

Chemicals














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4















5


L-(+)-isoleucine

















6




20 degC Pt

50 degC Ag

70 degC Cu Mo Pd Rh



130 degC In Mg

150 degC Sr





the vacuum line










7





























8



























9








10













11






12










13













yield




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15












16


















17



















sidebands









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shown in Fig S16c







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327



















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53 64





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346 97 68 74




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L-(+)-isoleucine

















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70 degC Cu Mo Pd Rh



130 degC In Mg

150 degC Sr





the vacuum line










7





























8



























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11






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yield




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150 degC Sr





the vacuum line










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8



























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70 degC Cu Mo Pd Rh



130 degC In Mg

150 degC Sr





the vacuum line










7





























8



























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11






12










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yield




14

















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16


















17



















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sidebands









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









10













11






12










13













yield




14

















15












16


















17



















sidebands









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









11






12










13













yield




14

















15












16


















17



















sidebands









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









12










13













yield




14

















15












16


















17



















sidebands









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









13













yield




14

















15












16


















17



















sidebands









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









14

















15












16


















17



















sidebands









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









15












16


















17



















sidebands









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









16


















17



















sidebands









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









17



















sidebands









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









18








nanocomposite













19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









19

























20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









20
















shown in Fig S16c







21


327



















22





samples


53 64





23











346 97 68 74




24









21


327



















22





samples


53 64





23











346 97 68 74




24









22





samples


53 64





23











346 97 68 74




24









23











346 97 68 74




24









24









SUPPLEMENTARY INFORMATION...immersed in an oil bath between 20 and 130 °C (see Table S2). The...

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Transcript of SUPPLEMENTARY INFORMATION...immersed in an oil bath between 20 and 130 °C (see Table S2). The...