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Studies on Hydrogen Storage in Carbon Materials

B.Viswanathan*, S. Ramaprabhu#, P.Selvam*, Prathap Haridass$, S. Rajalakshmi &, K.S.Dhathatreyan& and Pani@

*National Centre for Catalysis Research, Department of Chemistry #Alternative Energy and Nanotechnology Laboratory (AENL),

Nano Functional Materials Technology Centre (NFMTC), Department of Physics

$Department of Materials and Metallurgical EngineeringIndian Institute of Technology Madras, Chennai 600 036&ARC Centre for Fuel Cell Technology, and @Nanoram

Store and generate

HYDROGEN FUTURE: FACTS AND FALLACIES: CAUTION

[M. Aulice Scibioh and B. Viswanathan, Bulletin of the Catalysis Society of India, vol.3, pp.72-81(2004)]

A transition to a ‘hydrogen economy’ is a sea change in our energy infrastructure and is not to be taken lightly. As an energy carrier, hydrogen is to be compared to electricity, the only wide spread and viable alternative. When hydrogen is employed to transmit renewable electricity, only 50% can reach the end user due to losses in electrolysis, hydrogen compression and the fuel cell. The rush into a hydrogen economy is neither supported by energy efficiency arguments nor justified with respect to economy or ecology. In fact, it appears that hydrogen will not play an important role in a sustainable energy economy because the synthetic energy carrier cannot be more efficient than the energy from which it is made. Renewable electricity is better distributed by electrons than by hydrogen. Consequently, the hasty introduction of hydrogen as an energy carrier cannot be a stepping stone into a sustainable energy future. The opposite may be true. Because of the wastefulness of a hydrogen economy, the promotion of hydrogen may counteract all reasonable measures of energy conservation. Even worse, the forced transition to a hydrogen economy may prevent the establishment of a sustainable energy economy based on an intelligent use of precious renewable resources.

Transition to Hydrogen Economy

Production

Storage

DistributionChoice limited

Metal HydrideMOF

Petrol dispensing station

• Broad-based use of hydrogen as a fuel– Energy carrier analogous to electricity– Produced from variety of primaryenergy sources– Can serve all sectors of the economy: transportation, power, industry,buildings and residential– Replaces oil and natural gas as thepreferred end-use fuel – Makes renewable and nuclear energy “portable” (e.g. transportation needs)• Advantages:– Inexhaustible– Clean– Universally available to all countries

Transition to a “Hydrogen Economy”

Before and Now

Hydrogen Storage some Directions

Situation and Questions Situation and Questions

Production, storage and application - challenges of hydrogen economy

Solid state storage – remarkable but not reproducible 6.5 wt% - desired level (according to original DOE standards) Demands consistent and innovative practice

(i) Are the carbon materials appropriate for solid state hydrogen storage?

(ii) If this were to be true, what type of carbon materials or what type of treatments for the existing carbon materials are suitable to achieve desirable levels of solid state hydrogen storage?

(iii) What are the stumbling blocks in achieving the desirable solid state hydrogen storage?

(iv) Where does the lacuna lie? Is it in our theoretical foundation of the postulate or is it in our inability to experimentally realize the desired levels of storage?

Coordination number is variable/expandable Promote new morphologies Covalent character retention Variable hybridization possible Geometrical possibilities/size considerations Meta-stable state Similar to biological architectures “Haeckelites” Boron and nitrogen doped graphitic arrangements promise important applications.

Why carbon materials for solid Why carbon materials for solid state hydrogen storage?state hydrogen storage?

MaterialTemp

(K)Pressure

(bar)Wt% Group

GNF (Herring bone) RT 113.5 67.6 Chambers et al., (1998)

Graphitic Nano Fibers RT 101 10 Fan et al ., (1999)

Graphitic Nano Fibers RT 80-120 10 Gupta et al., (2000)

SWNTs (low purity) 273 0.4 5-10 Dillon et al., (1997)

SWNTs (high purity) 80 70-180 8.25 Ye et al., (1999)

SWNTs (50% purity) RT 101 4.2 Liu et al ., (1999)

SWNTs (high purity + Ti alloy)

300-600 0.7 3.5-4.5 Dillon et al., (1999)

Li-MWNTs 473-673 1 20 Chen et al., (1999)

Li-MWNTs (K-MWNTs) 473-673 1 2.5 (1.8) Yang et al., (2000)

MWNTs RT Ele.chem <1 Beguin et al., (2000)

CNF RT 1-100 0.1-0.7 Poirier et al., (2001)

SWNTs 300-520 1 0.1 Hirscher et al., (2000)

Various CNM RT 35 <0.1 Tibbets et al., (2001)

SWNTs (+ Ti alloy) RT 0.8 0 Hirscher et al., (2001)

Hydrogen storage capacity reported in carbon nanostructuresHydrogen storage capacity reported in carbon nanostructures

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A plot of the reported hydrogen storage capacities of CNTs from the literature versus their year of publication. Reprinted with . Seung Jae Yang , Haesol Jung , Taehoon Kim , Chong Rae Park, Recent advances in hydrogen storage technologies based on nanoporous carbon materials, Progress in Natural Science: Materials International, Volume 22, Issue 6, 2012, 631 – 638, http://dx.doi.org/10.1016/j.pnsc.2012.11.006

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1. Processing of carbon based nanostructured materials

2. Doping of Nitrogen/Boron on carbon based nanostructured materials

3. Dispersion of Pd metal nanoparticles on Boron/Nitrogen doped carbon based nanostructured materials

4. Characterization of these materials by XRD, SEM, HRTEM, XPS

6. Measurement of the hydrogen absorption/adsorption and kinetics of sorption using pressure reduction facility

7. Development of novel low cost Carbon based materials with a hydrogen storage capacity of 4-5 wt% hydrogen at room temperature and moderate pressure

Research objectives

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Hydrogen exfoliated GrapheneHydrogen exfoliated Graphene

20 nm 5 nm

Materials investigated for hydrogen storage

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Pristine carbon nanostructures Few layer graphene (G)

Nitrogen / Boron doped Few layer graphene (N-G)

Acid functionalized Few layer graphene (f-G)

Pd metal nanoparticles decorated acid functionalized few layer graphene (Pd/f-G)

Pd metal nanoparticles decorated Nitrogen doped few layer graphene (Pd/N-G)

Chemical modifications

Acid functionalization Nitrogen/Boron doping

Pd transition metal doping

NITROGEN DOPING

Treating Graphene with nitrogen plasma

for 30 min using RF sputtering

Chamber pressure ~ 0.05 mbar

RF power ~ 120 W

Aluminum disc was used as target

Nitrogen Plasma

Acid functionalization leads to the agglomeration of graphene sheets

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Characterizations of Pd/acid functionalized grapheneFTIR

XRD

f-Graphene

Pd/f-Graphene

Graphene

GGraphene Pd/f-Graphene

Graphene Pd/f-Graphene

Pd metal loading is 20 wt%Graphene

Graphite

GO

Pd/f-G Pd nanoparticle size ~ 6.6 nm

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Pd

C

O

Characterizations of Pd/nitrogen doped graphene

Graphene(G)

N-G

Pd/N-G

Pd metal loading is 20 wt%16

XPS spectra

High resolution XPS spectra of (a) C 1s (b) N 1s (c) Pd 3d and (d) O 1s orbital of Pd/N-G

Nitrogen content in Pd/N-G :7 atomic %

Raman spectra

Pd

C

O

N-Graphene

N-Graphene

Pd/N-Graphene

Pd/N-Graphene

Pd nanoparticle size ~ 3.1 nm

Microscopes images of Pd/nitrogen doped graphene

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Hydrogen adsorption isotherms of graphene composites

Graphene

N-Graphene

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Note the comparison between Graphene and heteroatom containing graphene

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Pd/f-Graphene

Pd/N-Graphene Pd/B-Graphene

Hydrogen adsorption isotherms of graphene composites

Samplewt% of hydrogen

stored at 25 °C and 20 bar

wt% of hydrogen stored at 25 °C and

32 barGraphene 0.53 0.65

N-Graphene 0.90 1.30 Pd bulk 0.61 0.65 Pd NPs 0.72 0.74

Pd/f-Graphene 1.75 2.50Pd/N-Graphene 2.10 3.80Pd/B-Graphene 3.60 5.00

(Patent to be filed (2014)

Comparison of hydrogen adsorption isotherm values for different carbon nanocomposites

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MECHANISM

1) Nitrogen/Boron doping effect on graphene support and Pd

nanoparticlesNitrogen/Boron doping can induce atomic charge density over graphene surface that enhances the interaction between carbon atoms and hydrogen molecules.

Nitrogen/Boron doping of graphene surface leads to high dispersion, small particle size and strengthened interaction of catalyst metal nanoparticles over the support.

Increase in hydrogen storage capacity of Pd/chemically modified graphene samples are due to

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SUMMARY

Graphene and GNP were chemically modified by acid functionalization and nitrogen doping for the dispersion of 3d transition metal nanoparticles.

Nitrogen doping provides high dispersion, small particle size and strengthened interaction of catalyst metal nanoparticles over the support.

Pd nanoparticles decorated Boron doped graphene gives an hydrogen storage capacity of 5.0 wt% at room temperature and 3.2 MPa pressure.

Enhancement in hydrogen storage capacity of Pd-Graphene nanocomposite is due to heteroatom doping and spillover mechanism.

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Work is in progress to achieve 5.0 wt% at room temperature and 2.0 MPa pressure.

Future plan

Studies on Hydrogen storage in carbon materials( No.103/140/2008-NT)

PI Prof.B.Viswanathan, Head, NCCR, Department of Chemistry, IIT Madras, Chennai

Co-PI: •Dr.K.S.Dhathathreyan, CFCT,ARCI, • Prof. A.R.Phani, NanoRam

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TGA with MS, Sieverts apparatus and ASAP TGA with MS, Sieverts apparatus and ASAP

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Major Equipments procured Major Equipments procured

Before CarbonizationAfter CarbonizationLemon Outer

Activated carbons from different precursors Activated carbons from different precursors

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Characterisation and hydrogen absorption studies Characterisation and hydrogen absorption studies

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Schematic of Hydrogen storage Apparatus

1 7

5

6

3

2

4

Part - 1 Part -21. Manifold Pressure

Gauge (0-150 bar) 2. H2 gas inlet3. Vacuum pump 4. Connecting channel 5. Reaction Chamber6. Vent 7. RC pressure Gauge (0-25

bar)

∆nH2 =P Man. V Man P RC. (V RC + Vman+ Vtub- Vsam )

Z (PMan,T) R. TMan Z (PRC,T) R. TRC

The total amount of hydrogen adsorbed by the sample can be :

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0.0 0.5 1.0 1.5 2.0 2.50

10

20

30

40

P (

bar)

H (wt%)

100 75 50 25

Hydrogen storage capacity for corn cob , Jute , TSC, Cotton Hydrogen storage capacity for corn cob , Jute , TSC, Cotton

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Hydrogen storage datalog of Cotton-800-2hr

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Sample SA (m2/g) MPV (cm3/g) H capacity wt % TSC-1 353 0.14 0.27TSC-2 672 0.27 TBDTSC-3 785 0.31 TBDTSC-P 775 0.08 TBD2%Pd-TSC-1 280 0.1 TBDPSC-1-600 672 0.28 1.47PSC-3-600 1356 0.56 1.67PSC-P 750 0.04 1.43MWTSC-50 0.67MWTSC-75 1.19MWTSC-100 1.36TSC-3-700 1770 0.59 4.12Jute-700-1hr 382 0.16 0.53Jute-700-1hr(1:1) 894 0.35 0.82Jute-700-1hr(1:3) 1224 0.43 1.2Jute-700-1hr (1:5) 1141 0.42 0.97Cotton-600-2hr 444 0.19 1.2Cotton-700-2hr 526 0.21 1.5Cotton-800-2hr 1279 0.46 4.2 

Consolidated data of all the samples at RT and at 40 barConsolidated data of all the samples at RT and at 40 bar

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PUBLICATIONS

Publications •Vinayan B P., Rupali Nagar, K. Sethupathi and S. Ramaprabhu, The Journal of Physical Chemistry C, 115, 15679, (2011).•Vinayan B P, K. Sethupathi and S. Ramaprabhu, Transactions of the Indian Institute of Metals, 64, 169, (2011).•Vinayan B P, K.Sethupathi and S.Ramaprabhu, Journal of Nanoscience and Nanotechnology, 12, 1, (2012)•Vinayan B P, Rupali Nagar, and S. Ramaprabhu, Langmuir, 28,7826, (2012).•Transition metal - graphene based hydrogen storage nanomaterial (Indian patent) filed (2012).•Chemically modified- carbon based hydrogen storage material (patent) to be filed (2014).

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Publications/ Paper1. Activated carbons derived from Tamarind seeds- T.Ramesh kumar, N.Rajalakshmi and K.S.Dhathathreyan, Communicated (2013)2. Pt loaded on carbon derived from corn cobs for hydrogen storage - R.Karthikeyan, N.Rajalakshmi and K.S.Dhathathreyan Communicated (2013)3. . Jute fibres based activated carbons for Hydrogen storage , M. Vivekanandan, T.Ramesh kumar, N.Rajalakshmi and K.S.Dhathathreyan - Communicated (2013)4. Carbon from Cotton as hydrogen storage medium– T.Ramesh kumar, N.Rajalakshmi and K.S.Dhathathreyan In preparation (2014)5. Hydrogen storage from composites based on Mg and activated carbon derived from tamarind seeds(2014).Conferences:6. T.Ramesh, G.Subashini, N.Rajalakshmi and K .S.Dhathathreyan , Activated Carbon from Tamarind Seeds- Promising Hydrogen storage material , Paper presented at the National conference on Advanced materials , NCAMA-2013 at NIT, Trichy during 4th and 5th April 2013

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0 20 40 60 80 100-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Room temperature

Hyd

roge

n ad

sorb

ed (w

t%)

Pressure (bar)

a)

0 20 40 60 80

0.0

0.1

0.2

0.3

0.4

0.5 Liquid N

2 temperature

Hyd

roge

n ad

sorb

ed (w

t%)

Pressure (bar)

b)

Boron substituted carbon materials and hydrogen absorption capacity for comparison purpose ( by another independent group)

7th April 2008 NCCR 34

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