Download Hydrogen: Water, Sun and Catalysts

Hydrogen: Water, Sun and Catalysts
Marc Fontecave
Laboratoire de Chimie et Biologie des Métaux, Université Joseph Fourier, CNRS, CEA/DSV/iRTSV
CEA-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
V. Artero
Y. Oudart
A. Fihri
S. Canaguier
A. Legoff
Need for new fuels from renewable sources
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 CO2.
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).
Energy global consumption
(Total 13.5 TW)
5
4.52
4
2.7
3
2.96
TW
2
1.21
0.828
1
0.286
0.286
0
oil
Gas
coal
Hydro Biomass
Renew
Nuclear
Production cost of energy
(U.S. 2004)
25-50¢
Cost, ¢/kW-hr
25
20
Storage
15
10
1-4¢
2.3-5.0¢ 6-8¢
5-7¢
6-7¢
5
0
coal
Gas
Courtesy of Nate Lewis, Caltech
oil
wind
Nuclear
Solar
Potential of renewable energy sources
TW
1000000
100000
10000
1000
100
10
1
0.1
Hydro
Tides &
currents
wind
Geotherm
solar
Current
Consumption
Powering the planet with solar fuels
SUN: The energy solution ! But how to store it ?
Solar energy:
3x1024 joules/year
= 10000 x world population
supply
(available for
billions of years ) !!
Powering the planet with solar fuels
SUN: The energy solution ! But how to store it ?
Electricity
(batteries)
Solar energy:
3x1024 joules/year
Photo
bioproduction
Water
(bio)
photolysis
Water
electrolysis
Cracking
Biomass
(Photo)
fermentation
H2
= 10000 x world population
supply
(available for
billions of years ) !!
Powering the planet with solar fuels
SUN: The energy solution ! But how to store it ?
Photovoltaics
>100000 TW/yr
(reduce the cost 10-fold)
Electricity
(storage:
batteries)
Solar energy:
3x1024 joules/year
= 10000 x world population
supply
(available for
billions of years ) !!
13 TW/yr
20 TW/yr (2030)
25 TW/yr (2050) ?
~160,000 km2 of photovoltaic panels
can satisfy the énergetic demand in the US (3.3 TW)
>100000 TW/yr
Solar energy:
3x1024 joules/year
= 10000 x world population
supply
(available for
billions of years ) !!
Photo
bioproduction
Biofuels
Biomass
100 TW/an
13 TW/yr
20 TW/yr (2030)
25 TW/yr (2050) ?
THE IDEAL CYCLE
Hydrogen: why ?
hydrogen
air
FUEL CELLS:
Conversion of chemical energy
in electrical energy
H2
air
water
2H+ + 2e-
2 H2 + O2
O2 + 4H+ + 4e-
2 H2O
∆H = - 570 kJ.mol-1
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).
2H2O
Production of hydrogen : reforming
CH4 + H2O
CO + 3 H2
CO + H2O
CO2 + H2
CH4 + 2 H2O
CO2 + 4 H2
800°C, 20 bars
Cata: Ni
∆H = + 165 kJ.mol-1
Production NH3 (50%)
Reforming factory (Air Liquide)
Chemicals (MeOH, H2O2,..) (13%)
Refinery (37%)
Renewable Energies
soleil
(photovoltaics, wind,
hydraulic,…)
ELECTROLYSIS
Biomass
Nuclear
H2
H2O
THERMOCHEMICAL
TRANSFORMATION
GAZEIFICATION
HEAT
PHOTOLYSIS
sun
Biohydrogen: cyanobacteria, microalgea, hydrogenases, bioinspired catalysts
H2 production:
The question of catalysis
Pt: the best catalyst
Pt: an expensive metal
Pt : an unsustainable metal
Rh
500 millions of vehicles (av 75 kW)
0.4 g Pt/kW (2010); recycling 50%
Pt: stocks consumed
within 15 years
Gordon et al. PNAS 2006
Nature, 2007, 450,334
Pt
Bioinspired
chemical systems
The catalysis solution ?
« Biological » H2 photoproduction
Photosynthetic
microorganisms
CO2
microalgae
cyanobacteria
Rubisco
H+ H
2
H2ase
Amidon
NADPH
FNR
QA
PQ
PS II
H2O
Mn
Fd
Cyt
b6/f
Pc
O2
Ni, Fe
PS I
Production of H2: from sun and water ?
The « tough » part
The « easy » part
(somewhat tough)
- ∆G >>0
- removal of 4 H+ and four e- from water
- ∆G <0
- formation of an O-O bond
- combining 2 H+ and 2 e- light collection and conversion
- formation of an H-H bond
From W. Lubitz, En. Env. Sci. 2008
Source of electrons
-Electricity (electrolysis)
-Sacrificial reductant + hν
ν
Biomimetic production of H2
Catalysts:
-Pt, Rh,…
-Hydrogénases
NiFe-[H2]ase from Allochromatium vinosum
adsorbed on graphite shows a Nernstian behavior
as reversible as colloïdal platinum
Eisos = -400 mV/ENH
(30°C; pH 7; 0,1 bar H2)
- bioinspired
complexes
Ni-Fe Hydrogenases and model compounds
NiFe-[H2]ase adsorbed on graphite
shows a Nernstian behavior
as reversible as colloïdal platinum
Volbeda, A. et al., Nature (1995), 373, 580-587.
Volbeda, A. et al., J. Am. Chem. Soc. (1996), 118, 12989-12996.
Model compounds
Structural vs Functional
2
H+
+2
e-
H2
E = -400 mV vs SHE
(30°C; pH 7; 0,1 bar H 2)
1500-9000 TON/s
The biomimetic approach
Canaguier et al., Dalton Trans., 2008
Darensbourg (1996)
Pohl
Darensbourg
Evans
Schröder
Schröder
Schröder
Sellmann
Tatsumi (2005)
Schröder
Schröder
Bouwman*
No activity reported for dinuclear biomimetic nickel-iron complexes
Towards Ni-Ru(CO) complexes….
Why Ru?
Sigolène
Canaguier
Ru2+ accomodates both hard
and soft ligands (H-, H2).
Affinity for π-acid ligands and H2
Ru2+ complexes activate H2
(Noyori, Watanabe, Ogo, Rauchfuss,…)
Ligands: diimines, diphosphines,…
Electron-donor
NiN2S2 or NiS4 ligands
comparable to bipy (Darensbourg 2005)
Easy synthesis
Towards Ni-Ru complexes ….
[Ni(emi)]2-
H2emi: N,N’-ethylenebis
(2-mercaptoisobutyramide)
[Ni(xbsms)]
H2xbsms: 1,2-bis(4-mercapto-3,3dimethyl-2-thiabutyl)benzene
V. Artero, M. Fontecave et al
Inorg. Chem. 2006, 45, 4334
Eur. J. Inorg. Chem. 2007
Towards Ni-Ru complexes ….
Oudart et al. Inorg. Chem. 2006, Eur. J. Inorg. Chem. 2007
S. Canaguier et al. Submitted 2009
Electrocatalytic proton reduction
Electrocatalytic behavior:
Cyclic Voltammetry (CV)
E /V vs Ag/AgCl
-2
-1,5
-1
Et3NH+
-0,5
0
0,5
1
Bulk electrolysis: H2 production
Controlled Potential Coulommetry (CPC
20 µA
DMF; 100 mV.s-1
Glassy carbon
H2
H+
Eher= - 1,44 V vs Ag/AgCl
24 turnovers in 4h at -1,6V vs Ag/AgCl
S. Canaguier, V. Artero, M. Fontecave, unpublished
Hg; DMF; 50 eq Et3NH+
100 % yield
Stable after several runs
« HER potential » and « HER overvoltage »
E = -400 mV vs SHE (30°C; pH 7; 0,1 bar H 2)
1500-9000 TON/s
H2
2 H+ + 2 e -
H2O
DMF
Standard Potential
-0,78 (Pt:-0.95)
Eher(Et3NH+/H2)
(V vs Ag/AgCl)
0
Biomimetic catalysts
- 1,44 -1,60
-1,65
-2
-1
« HER overvoltage »
17
(CO force constant vs Eher)
16,5
kCO / mdynes.Å–1
Increasing electron
density decreases HER
16
15,5
Felton et al., Inorg. Chem., 2006, 45, 9181.
Y. Oudart, V. Artero, J. Pécaut, C. Lebrun, M. Fontecave,
Eur. J. Inorg. Chem., 2007
[NiFe] H2ase from D. gigas
15
-2,5
-2
-1,5
E her /V vs Ag/AgCl
-1
-0,5
Conclusion…
Ni-Ru complexes as functional models
for [Ni-Fe]hydrogenases
-Easy to synthesize
-Stable in solution
-High yields and high turnover numbers
during proton reduction to hydrogen
-High overvoltages (0.5-0.8 V)
More biomimetic…Less expensive…
Unpublished results
Abundance (ppm)
Pt
Ni
Ru
Mn
Fe
terrestrial crust
oceans
0,01
105
0,01
1400
70 700
/
0,0005
/
0,002
0,01
Price (€/g)
93
23
0,194
0.009
15,7
2
0.0003
0,088
0.000058
0,053
Towards Ni-M complexes ….
Oudart et al. Inorg. Chem. 2006
Eur. J. Inorg. Chem. 2007
Photo-production
of hydrogen
M. FONTECAVE
Laboratoire Chimie et Biologie des Métaux
UMR 5249-CEA/CNRS/UJF
Grenoble - France
P.A. Jacques
V. Artero
A. Fihri
Photobiohydrogen and model reaction
RuBP
H2
CO2
H+
[CHO]n
Cycle
decycle
Calvin
Calvin
H2
2 H+
+
Hydrogénase NADP NADPH
Fd
FNR
Qa
LHC
2 H2O
PSII
P680
PQ(H)2
O2 +
4
cytb6
Catalyst
M
hν
e-
Covalent bond
s
Photosensitizer
PSI LHC
P700
cytf
Pc
Sacrificial reducing agent
H+
∆rG°= 476 kJ.mol -1
4 photons × 1.23 eV
4 electrons involved
Ox
∆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)
2+
N
N
N
Ru
e-
N
N
e½ H2
N
M
H+
Find the good catalyst M
Find the good photosensitizer
Make a multi-functional (supramolecular) system
Make this reaction useful (sacrificial electron donor: H2O)
Light-harvesting
center
N
N
N
Ru
N
N
M
Catalyst
N
Linker: tunes the electronic communication
between the two components
Best catalysts:
overvoltage, TOF,..
NH3+
NC
pKa= 7,6
Eher = - 0.4 V vs Ag/AgCl in CH3CN
92 TON.h-1 (- 0.5 V)
Cobaloximes as functional models for hydrogenases. 2. Proton electroreduction catalyzed
by difluoroboryl-bis(dimethylglyoximato)-cobalt(II) complexes in organic media
C. Baffert, V. Artero, M. Fontecave
Inorg. Chem.. 2007, 46, 1817-1824
bz
N
Cy
P
bz
N
P
Cy
Cy
P
Ni
P
Cy
bz
N
N
CF3SO3H
pKa= 2.6
bz
H2/Et3N
Eher = -0.4V vs Ag/AgCl
Dubois et al. J. Am. Chem. Soc., 2006.
One of the rare catalyst for H2 oxidation
E =-0.27 vs Ag/AgCl
N
N
N
Ru
A Ru-Co complex
M
N
N
N
Acetone
+
3h, T.A
E /V vs Ag/AgCl
-2
-1.5
-1
-0.5
CoI
0
0.5
1
CoII
DMF 0.1M n-Bu4NBF4 as
supporting electrolyte
glassy carbon electrode,
v = 100 mV.s-1
5µA
H2 Photoproduction
60
acetone
50
TON
40
30
20
CH3CN
10
0
0
1
Hg lamp (> 350 nm)
Acetone
Et3N : 100 equiv.
Et3NHBF4 : 100 equiv
H2 : GC analysis
2
3
4
irradiation time /h
Fihri, A.; Artero, V.; Razavet, M.; Baffert, C.; Leibl, W.; Fontecave, M.,
Cobaloxime-Based Photocatalytic devices for Hydrogen Production.
Angewandte Chemie, International Edition 2008
½ H2
Acetone
60
Et3N•+
20
10
0
Et3N
CH3OH
H+
CH3CN
30
DMF
40
1,2-dichloroéthane
50
A tunable supramolecular system:
1. the coordination sphere
140
120
100
E°(Co
II/CoI)
= -0.9 V vs Ag/AgCl
E°(Co II/CoI) = -0.41 V vs Ag/AgCl
E°(CoII/CoI) = -0.23 V vs Ag/AgCl
80
60
40
20
0
TO N
A tunable supramolecular complex
2. the linker
+
2 TON
56 TON
+ exces dmgH2
17 TON
120 TON
Fihri, Artero, Leibl, Fontecave, Angew. Chem. 2008
A tunable supramolecular complex
3. the photosensitizer
Turnovers
9
> 380 nm
210
273
Fihri, Artero, Fontecave, Dalton Trans 2008
CH3CN
Et3N
TON = 56
Aqueous acetate buffer
EDTA pH 5
TON = 4.8
Vos et al.
Angew. Chem. Int. Ed.
2006.
Sakai et al.
J. Am. Chem. Soc.
2006.
acetone
Et3N
TON = 120
CH3CN/H2O
Dimethylaniline
TON = 60
Brewer et al.
J Am. Chem. Soc.
2007
Artero, Fontecave et al.
Angew. Chem. Int. Ed.
2008.
Aqueous buffer
ascorbate
TON = 20
The « Graal » : H2O as the source of electrons
2760
Bernhard
JACS 2007
100-600
Thummel
Inorg. Chem. 2008
TN: 250
Llobet
[Ru(µ
µ-OAc)(bpp)(terpy)2]
Angew chem 2008, 47, 5830
Ce(IV)
électrode
M’
500
Bonchio, Hill
Angew. 2008
Co(PO4)
Nocera
Science 2008
1000
Dismukes
Angew. 2008
Project GRAFTHYDRO
Bio-inspired nanomaterials for Hydrogen evolution:
towards alternatives to platinum nanoparticles
H2
Laboratoire de Chimie et Biologie des métaux
UMR 5249 CEA/CNRS Université Jospeh Fourier
Marc Fontecave
Vincent Artero
Alan Legoff
Laboratoire de Chimie des Surfaces et Interfaces
CEA Saclay
Serge Palacin
Bruno Jousselme
Photoelectrochemical cell: water photoelectrolysis
2H2O = O2 + 2H2
e-
Cathode
H+
H+
Photocathode
H2O
H+
O2
H2
Photoanode
SC-n : Fe2O3/WO3
O2
or
H2
Best catalysts:
overvoltage, TOF,..
NH3+
NC
pKa= 7,6
Eher = - 0.4 V vs Ag/AgCl in CH3CN
92 TON.h-1 (- 0.5 V)
Cobaloximes as functional models for hydrogenases. 2. Proton electroreduction catalyzed
by difluoroboryl-bis(dimethylglyoximato)-cobalt(II) complexes in organic media
C. Baffert, V. Artero, M. Fontecave
Inorg. Chem.. 2007, 46, 1817-1824
bz
N
Cy
P
bz
N
P
Cy
Cy
P
Ni
P
Cy
bz
N
N
CF3SO3H
pKa= 2.6
bz
H2/Et3N
Dubois et al. J. Am. Chem. Soc., 2006.
Eher = -0.4V vs Ag/AgCl
One of the rare catalysts for H2 oxidation
E =-0.27 vs Ag/AgCl
Bio-inspired nanomaterials for Hydrogen evolution
Hydrogenases
Bio-inspired catalysts
Electrocatalytic activity demonstrated in solution
Dubois et al., J. Am. Chem. Soc. 2007,128, 358
European patent application EP-08 290 988.8
NOVEL MATERIALS AND THEIR USE FOR THE
ELECTROCATALYTIC EVOLUTION OR UPTAKE OF H2
What about the electrocatalytic activity of the
complexes grafted on the electrodes ???
MWNTs electrode functionalization
with metal catalysts
(Eher= -0.3 V vs Ag/AgCl)
- 0.2 V
RNH2
399.9
N 1s
RNH3+
401.6
Ni
200 Counts/s
2p3/2
856.0
2p1/2
873.9
P 2p
132.2
ITO
500 Counts/s
405
MWNTs
400
395
Binding energy (eV)
890
135
n = 1.5 10-9 mol.cm-2
880
130
X-ray Photoelectron Spectroscopy (XPS)
Scanning Electron Microscopy (SEM)
870
860
Binding Energy (eV)
850
Electrocatalytic properties of the
modified electrodes
E /V vs Ag/AgCl
H+
H2
-0,8 -0,6 -0,4 -0,2 0,0 0,2
[DMF-H]+
CH3CN
e2OOµA
-0.3 V
(overvoltage: 0.2V)
DMFH+: pKa=6.1 in CH3CN
E°= - 0.1 V vs Ag/AgCl
Controlled potential coulometry
(-0.5 V vs Ag/AgCl)
CH3CN /[DMFH](OTf) 60 mM
GC analysis of H2
European patent application EP-08 290 988.8
Ni-ITO-MWCNT
n = 1.5 10-9 mol.cm-2
>20.000 turnovers within 1h !! (6 s-1)
94% faradaic yield
No evidence for loss of activity over hours
Activity in water !! (N. Guillet, LITEN, CEA)
Ring (Pt)- Disk(vitreous C + Nafion + Ni-NTC) configuration
H2SO4 0.1 M
Rotating-disk electrode measurements
H2 evolution with 18 mV overvoltage
Membrane (Nafion)- Gas Diffusion Layer (Ni-NTC) half-cell
H2SO4 0.1 M
A material compatible
with PEM technology
(Nafion membrane,
Acidic conditions)
Hydrogen: Water, Sun and Catalysts
Marc Fontecave
Laboratoire de Chimie et Biologie des Métaux, Université Joseph Fourier, CNRS, CEA/DSV/iRTSV
CEA-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
V. Artero
Y. Oudart
A. Fihri
S. Canaguier
A. Legoff