hydrogen: water, sun and catalysts - ias.ac.in · electrolysis sun: the energy solution ... ps ii...
TRANSCRIPT
V. ArteroY. OudartA. FihriS. CanaguierA. Legoff
Hydrogen: Water, Sun and Catalysts
Marc FontecaveLaboratoire de Chimie et Biologie des Métaux, Université Joseph Fourier, CNRS, CEA/DSV/iRTSV
CEA-Grenoble 17 rue des martyrs 38054 Grenoble cedex 9, [email protected]; Phone: (0033)438789103 ; Fax: (0033)438789124
Collège de France, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05
Doubling of the energetic supply in 40-50 years-World population increase(2050 from 6 to 9 billions)-economical growth
Limitation of the emission of green-house effect CO 2.
Limitation of the fossil sources of energy (petrol, gas, coal) coal: 200 years; gas: 100 years; oil: 50 years. Uranium: < 100 years, (surgenerators 300 years).
Need for new fuels from renewable sources
Energy global consumption(Total 13.5 TW)
Gas Hydro Renew
4.52
2.7 2.96
0.286
1.21
0.2860.828
0
1
2
3
4
5
TW
oil coal Biomass Nuclear
(U.S. 2004)
1-4¢ 2.3-5.0¢ 6-8¢ 5-7¢
Production cost of energy
6-7¢
25-50¢C
ost,
¢ /kW
-hr
0
5
10
15
20
25
coal Gas oil wind Nuclear Solar
Courtesy of Nate Lewis, Caltech
Storage
Potential of renewable energy sources
Hydro Tides ¤ts
wind Geotherm solar CurrentConsumption
0.1
1
10
100
1000
10000
100000
1000000
TW
SUN: The energy solution ! But how to store it ?
Solar energy:3x1024 joules/year
= 10000 x world populationsupply
(available for billions of years ) !!
Powering the planet with solar fuels
Water electrolysis
SUN: The energy solution ! But how to store it ?
H2
Electricity(batteries)
Water(bio)
photolysis
Solar energy:3x1024 joules/year
= 10000 x world populationsupply
(available for billions of years ) !!
Cracking
(Photo)fermentation
Photobioproduction
Biomass
Powering the planet with solar fuels
Electricity(storage:batteries)
>100000 TW/yr
13 TW/yr20 TW/yr (2030)25 TW/yr (2050) ?
Photovoltaics(reduce the cost 10-fold)
~160,000 km2 of photovoltaic panels can satisfy the énergetic demand in the US (3.3 TW)
SUN: The energy solution ! But how to store it ?
Powering the planet with solar fuels
Solar energy:3x1024 joules/year
= 10000 x world populationsupply
(available for billions of years ) !!
Photobioproduction
Biomass
>100000 TW/yr
100 TW/an
Biofuels
Solar energy:3x1024 joules/year
= 10000 x world populationsupply
(available for billions of years ) !!
13 TW/yr20 TW/yr (2030)25 TW/yr (2050) ?
FUEL CELLS:Conversion of chemical energy
in electrical energy
2 H2 + O2 2 H2O∆∆∆∆H = - 570 kJ.mol -1
H2 2H+ + 2e-O2 + 4H+ + 4e- 2H2O
H2: 119930 kJ/kg; 33,3 kWh/kg(2.7 fold more than oil; 2.4 fold more than natural gas;5 fold more than coal).
Hydrogen: why ?
hydrogen
airwater
air
CH4 + H2O CO + 3 H2
∆∆∆∆H = + 165 kJ.mol -1
CO + H2O CO2 + H2
CH4 + 2 H2O CO2 + 4 H2800°C, 20 bars
Cata: Ni
Production of hydrogen : reforming
Production NH 3 (50%)
Chemicals (MeOH, H 2O2,..) (13%)
Refinery (37%)
Reforming factory (Air Liquide)
H2H2O
ELECTROLYSIS
HEAT
Renewable Energies(photovoltaics, wind,
hydraulic,…)
Biomass
THERMOCHEMICALTRANSFORMATION
GAZEIFICATION
PHOTOLYSIS
Biohydrogen: cyanobacteria, microalgea, hydrogenases, bioinspired catalysts
sun
Nuclear
soleil
Pt : an unsustainable metal500 millions of vehicles (av 75 kW) 0.4 g Pt/kW (2010); recycling 50%
Pt: stocks consumedwithin 15 years
Pt: an expensive metal
Pt: the best catalyst
Rh
Pt
Gordon et al. PNAS 2006Nature, 2007, 450,334
H2 production:The question of catalysis
Fd
PQ
PcH2O
Cytb6/f
H2ase
H+H2
NADPH
PS II PS I
FNRQA
O2
Rubisco
CO2
Amidon
Photosyntheticmicroorganisms
microalgaecyanobacteria
The catalysis solution ?« Biological » H2 photoproductionBioinspired
chemical systems
Mn
Ni, Fe
Production of H2: from sun and water ?
The « tough » part
- ∆G >>0- removal of 4 H+ and four e- from water- formation of an O-O bond- light collection and conversion
The « easy » part(somewhat tough)
- ∆G <0- combining 2 H+ and 2 e-
- formation of an H-H bondFrom W. Lubitz, En. Env. Sci. 2008
Biomimetic production of H2
Catalysts:
-Pt, Rh,…-Hydrogénases
- bioinspiredcomplexes
Source of electrons-Electricity (electrolysis)-Sacrificial reductant + hνννν
NiFe-[H2]ase from Allochromatium vinosumadsorbed on graphite shows a Nernstian behavior
as reversible as colloïdal platinumEisos = -400 mV/ENH
(30°C; pH 7; 0,1 bar H2)
Volbeda, A. et al., Nature (1995),373, 580-587.Volbeda, A. et al., J. Am. Chem. Soc. (1996), 118, 12989-12996.
Ni-Fe Hydrogenases and model compounds
2 H+ + 2 e- H2E = -400 mV vs SHE
(30°C; pH 7; 0,1 bar H 2)1500-9000 TON/s
Model compoundsStructural vs Functional
NiFe-[H2]ase adsorbed on graphite shows a Nernstian behavior
as reversible as colloïdal platinum
Darensbourg (1996) Pohl
Tatsumi (2005)
Bouwman*
Schröder
Sellmann
Darensbourg
Evans Schröder Schröder
Schröder Schröder
Canaguier et al., Dalton Trans., 2008
The biomimetic approach
No activity reported for dinuclear biomimetic nickel-i ron complexes
Towards Ni-Ru(CO) complexes….Why Ru?
Ru2+ accomodates both hard and soft ligands (H-, H2). Affinity for ππππ-acid ligands and H2
Ru2+ complexes activate H2(Noyori, Watanabe, Ogo, Rauchfuss,…)
Ligands: diimines, diphosphines,…
Electron-donorNiN2S2 or NiS4 ligands comparable to bipy (Darensbourg 2005)
Easy synthesis
SigolèneCanaguier
Towards Ni-Ru complexes ….
V. Artero, M. Fontecave et al Inorg. Chem. 2006, 45, 4334Eur. J. Inorg. Chem. 2007
[Ni(xbsms)]
[Ni(emi)]2-
H2emi: N,N’-ethylenebis(2-mercaptoisobutyramide)
H2xbsms: 1,2-bis(4-mercapto-3,3-dimethyl-2-thiabutyl)benzene
Oudart et al. Inorg. Chem. 2006, Eur. J. Inorg. Chem. 2007S. Canaguier et al. Submitted 2009
Towards Ni-Ru complexes ….
24 turnovers in 4h at -1,6V vs Ag/AgCl
Electrocatalytic behavior:Cyclic Voltammetry (CV)
E /V vs Ag/AgCl-2 -1,5 -1 -0,5 0 0,5 1
Et3NH+
20 µA
DMF; 100 mV.s-1
Glassy carbon
Eher= - 1,44 V vs Ag/AgCl
H+H2
Electrocatalytic proton reduction
S. Canaguier, V. Artero, M. Fontecave, unpublished
Hg; DMF; 50 eq Et3NH+
100 % yieldStable after several runs
Bulk electrolysis: H2 productionControlled Potential Coulommetry (CPC
« HER potential » and « HER overvoltage »
Felton et al., Inorg. Chem., 2006, 45, 9181.
« HER overvoltage »
Biomimetic catalystsDMF
Increasing electrondensity decreases HER(CO force constant vs Eher)
0 -2-1
-0,78 (Pt:-0.95)Standard Potential
-1,60 -1,65
Eher(Et3NH+/H2)(V vs Ag/AgCl)
2 H+ + 2 e- H2E = -400 mV vs SHE (30°C; pH 7; 0,1 bar H 2)1500-9000 TON/s
H2O
- 1,44
E her /V vs Ag/AgCl
k CO
/ mdy
nes.
Å–1
15
15,5
16
16,5
17
-2,5 -2 -1,5 -1 -0,5
[NiFe] H2ase from D. gigas
E her /V vs Ag/AgCl
k CO
/ mdy
nes.
Å–1
15
15,5
16
16,5
17
-2,5 -2 -1,5 -1 -0,5
[NiFe] H2ase from D. gigas
Y. Oudart, V. Artero, J. Pécaut, C. Lebrun, M. Font ecave, Eur. J. Inorg. Chem., 2007
Ni-Ru complexes as functional modelsfor [Ni-Fe]hydrogenases
-Easy to synthesize
-Stable in solution
-High yields and high turnover numbersduring proton reduction to hydrogen
-High overvoltages (0.5-0.8 V)
Conclusion…
Abundance (ppm)
terrestrial crust oceans Price (€/g)
Pt 0,01 / 93 Ni 105 0,0005 0,194 Ru 0,01 / 15,7 Mn 1400 0,002 0,088 Fe 70 700 0,01 0,053
More biomimetic…Less expensive…
Unpublished results
230.009
20.0003
0.000058
Photo-productionof hydrogen
M. FONTECAVELaboratoire Chimie et Biologie des Métaux
UMR 5249-CEA/CNRS/UJFGrenoble - France
P.A. JacquesA. Fihri V. Artero
CO2
Pc
P680
Qa
P700
PSIIcytb6
NADPH
O2 + 4 H+
2 H2O
FNR
NADP+
cytf
Cycle de Calvin
[CHO]n
PSILHCLHC LHCLHCPQ(H)2
FdHydrogénase
2 H+H2
RuBP
Calvin cycle
hν
Sacrificial reducing agentOx
e-
M
H+
s
Catalyst
Photosensitizer
H2
Covalent bond
∆rG°= 476 kJ.mol -1
4 photons × 1.23 eV4 electrons involved
∆rG°= 140 kJ.mol -1
1 photon × 1.45 eV 2 electrons involved
1.56 eV ( 800 mn) < Visible radiation < 3.12 eV (400 nm)
Photobiohydrogen and model reaction
N
N
N
N
N
N
Ru
2+
Me-
e-
½ H2
Find the good catalystM
Find the good photosensitizer
Make a multi-functional (supramolecular) system
N
N
N
NN
NRu M
Linker: tunes the electronic communicationbetween the two components
CatalystLight-harvesting
center
Make this reaction useful (sacrificial electron donor: H2O)
H+
NP
PN NiP
P
N
Cy
CyCy
Cy
N
bz
bz bz
bz
Dubois et al. J. Am. Chem. Soc., 2006.
Eher = -0.4V vs Ag/AgCl
Cobaloximes as functional models for hydrogenases. 2. Proton electroreduction catalyzed by difluoroboryl-bis(dimethylglyoximato)-cobalt(II) complexes in organic mediaC. Baffert, V. Artero, M. FontecaveInorg. Chem.. 2007, 46, 1817-1824
Eher = - 0.4 V vs Ag/AgCl in CH3CN92 TON.h-1 (- 0.5 V)pKa= 7,6
NC NH3+NC NH3+
CF3SO3HpKa= 2.6
One of the rare catalyst for H2 oxidationE =-0.27 vs Ag/AgCl
H2/Et3N
Best catalysts:overvoltage, TOF,..
+Acetone
3h, T.A
CoIICoI
DMF 0.1M n-Bu4NBF4 assupporting electrolyte glassy carbon electrode, v = 100 mV.s-1
5µA
-2 -1.5 -1 -0.5 0 0.5 1
E /V vs Ag/AgCl
N
N
N
NN
NRu M A Ru-Co complex
0
10
20
30
40
50
60
0 1 2 3 4irradiation time /h
TO
N
0
10
20
30
40
50
60
DM
F
CH
3CN
CH
3OH
Acetone
1,2
-dic
hlo
roét
han
e
H2 : GC analysis
acetone
CH3CN
H+
½ H2
Et3N
Et3N•+
H2 Photoproduction
Fihri, A.; Artero, V.; Razavet, M.; Baffert, C.; Leibl, W.; Fontecave, M., Cobaloxime-Based Photocatalytic devices for Hydrogen Production.Angewandte Chemie, International Edition 2008
Hg lamp (> 350 nm)AcetoneEt3N : 100 equiv.Et3NHBF4 : 100 equiv
0
20
40
60
80
100
120
140 TON
E°(Co II/CoI) = -0.9 V vs Ag/AgCl
E°(Co II/CoI) = -0.41 V vs Ag/AgCl
A tunable supramolecular system:1. the coordination sphere
E°(CoII/CoI) = -0.23 V vs Ag/AgCl
+ exces dmgH2 17 TON
+
2 TON
56 TON 120 TON
Fihri, Artero, Leibl, Fontecave, Angew. Chem. 2008
A tunable supramolecular complex2. the linker
210 2739
> 380 nmFihri, Artero, Fontecave, Dalton Trans 2008
Turnovers
A tunable supramolecular complex3. the photosensitizer
Sakai et al.J. Am. Chem. Soc.
2006.
Aqueous acetate bufferEDTA pH 5TON = 4.8
Vos et al.Angew. Chem. Int. Ed.
2006.
CH3CNEt3NTON = 56
CH3CN/H2ODimethylanilineTON = 60
Brewer et al.J Am. Chem. Soc.
2007
acetoneEt3NTON = 120
Artero, Fontecave et al.Angew. Chem. Int. Ed.
2008.
Aqueous bufferascorbateTON = 20
M’
[Ru(µµµµ-OAc)(bpp)(terpy)2]Angew chem 2008, 47, 5830
TN: 250Llobet
The « Graal » : H2O as the source of electrons
2760Bernhard
JACS 2007100-600
ThummelInorg. Chem. 2008
500Bonchio, HillAngew. 2008
1000Dismukes
Angew. 2008
Ce(IV)électrode
Co(PO4)Nocera
Science 2008
Project GRAFTHYDRO
Bio-inspired nanomaterials for Hydrogen evolution: towards alternatives to platinum nanoparticles
Laboratoire de Chimie et Biologie des métauxUMR 5249 CEA/CNRS Université Jospeh Fourier
Laboratoire de Chimie des Surfaces et InterfacesCEA Saclay
H2
Marc FontecaveVincent Artero
Alan Legoff
Serge PalacinBruno Jousselme
e-
Photoelectrochemical cell: water photoelectrolysis
H+
H+
H2
O2
H2O
H+
Photoanode
SC-n : Fe2O3/WO3
Cathode
or
Photocathode
H+
O2 H2
2H2O = O2 + 2H2
NP
PN NiP
P
N
Cy
CyCy
Cy
N
bz
bz bz
bz
Dubois et al. J. Am. Chem. Soc., 2006.
Eher = -0.4V vs Ag/AgCl
Cobaloximes as functional models for hydrogenases. 2. Proton electroreduction catalyzed by difluoroboryl-bis(dimethylglyoximato)-cobalt(II) complexes in organic mediaC. Baffert, V. Artero, M. FontecaveInorg. Chem.. 2007, 46, 1817-1824
Eher = - 0.4 V vs Ag/AgCl in CH3CN92 TON.h-1 (- 0.5 V)pKa= 7,6
NC NH3+NC NH3+
CF3SO3HpKa= 2.6
One of the rare catalysts for H2 oxidationE =-0.27 vs Ag/AgCl
H2/Et3N
Best catalysts:overvoltage, TOF,..
Hydrogenases
Bio-inspired catalystsElectrocatalytic activity demonstrated in solution
What about the electrocatalytic activity of the complexes grafted on the electrodes ???
Bio-inspired nanomaterials for Hydrogen evolution
European patent application EP-08 290 988.8 NOVEL MATERIALS AND THEIR USE FOR THE ELECTROCATALYTIC EVOLUTION OR UPTAKE OF H2
Dubois et al., J. Am. Chem. Soc. 2007,128, 358
N 1s
395400405
Binding energy (eV)
200 Counts/s
RNH2399.9
RNH3+
401.6
MWNTs
ITO
MWNTs electrode functionalizationwith metal catalysts
850860870880890
Binding Energy (eV)
500 Counts/s
2p1/2873.9
2p3/2
856.0Ni
850860870880890
Binding Energy (eV)
500 Counts/s
2p1/2873.9
2p3/2
856.0
850860870880890
Binding Energy (eV)
500 Counts/s
2p1/2873.9
2p3/2
856.0Ni
2p132.2
P
130135
X-ray Photoelectron Spectroscopy (XPS)
- 0.2 V
(Eher= -0.3 V vs Ag/AgCl)
n = 1.5 10-9 mol.cm-2 Scanning Electron Microscopy (SEM)
e-
H+
H2[D
MF
-H]+
-0,8 -0,6 -0,4 -0,2 0,0 0,2
E /V vs Ag/AgCl
2OOµA
European patent application EP-08 290 988.8
CH3CN
Electrocatalytic properties of the modified electrodes
>20.000 turnovers within 1h !! (6 s -1)94% faradaic yieldNo evidence for loss of activity over hours
Controlled potential coulometry(-0.5 V vs Ag/AgCl)CH3CN /[DMFH](OTf) 60 mMGC analysis of H2
n = 1.5 10-9 mol.cm-2
Ni-ITO-MWCNT
DMFH+: pKa=6.1 in CH3CNE°= - 0.1 V vs Ag/AgCl
-0.3 V(overvoltage: 0.2V)
Activity in water !! (N. Guillet, LITEN, CEA)
Ring (Pt)- Disk(vitreous C + Nafion + Ni-NTC) configurationH2SO4 0.1 MRotating-disk electrode measurements
H2 evolution with 18 mV overvoltage
Membrane (Nafion)- Gas Diffusion Layer (Ni-NTC) half-cellH2SO4 0.1 M
A material compatiblewith PEM technology(Nafion membrane,Acidic conditions)
V. ArteroY. OudartA. FihriS. CanaguierA. Legoff
Hydrogen: Water, Sun and CatalystsMarc Fontecave
Laboratoire de Chimie et Biologie des Métaux, Université Joseph Fourier, CNRS, CEA/DSV/iRTSVCEA-Grenoble 17 rue des martyrs 38054 Grenoble cedex 9, France
[email protected]; Phone: (0033)438789103 ; Fax: (0033)438789124
Collège de France, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05