Artificial photosynthesis for solar fuels

Stenbjörn Styring

Uppsala university

Swedish Consortium for Artificial Photosynthesis

1994-

Sw. Energy agency, Knut and Alice Wallenberg Foundation; EU; VR

0 10 20 30

The global concept

Nuclear Biomass Hydro others.....

TW40

80%

Fossil 2011; ca 17 TW years

Global energy use

Energy supply 2008, Sweden:

33 32 12 23 % of total

Local vs. global concept

Fossil NuclearBiomassHydro

Energy supply 2008, Sweden:

33 32 12 23 % of total

Local vs. global concept

Fossil Nuclear

Energy supply 2008; Germany

82 11 7 % of total

Fossil

BiomassHydro

TW

2050

0 10 20 30

The global concept

40

2011: 17 TW

80%

Fossil

Fossil

TW

2050

0 10 20 30

The global concept

Note! This comes from people that don´t use energytoday. They can not solve this by saving energy!!!

40

2011: 17 TW

80%

Fossil

Fossil

Renewable technologies (Sims et al, IPCC 2007) ElectricityTechnologically mature with markets hydroelectric; geothermal;in at least some countries woody biomass; onshore wind

landfill gas; bioethanol; siliconsolar cells.....

Technologically mature with small, new solid waste energy in towns;markets in few countries biodiesel; offshore wind; heat

concentrating solar dishes...

Under technological development thin film PV; tidal change; wavedemonstration plants, upcoming biomass gasification; pyro-

lysis; bioethanol from ligno-cellulose; thermal towers.......

Many give electricity

TW10 20

Everything is not electricity

2011; ca 17 TW yearsFossil

80%

Total production

TW10 20

80%

Electricity 17%

Fossil

Everything is not electricity

Total production

Final consumtion

TW10 20

80%

Electricity 17%The rest, 83% is used as fuel for many things

Fossil

Everything is not electricity

Total production

Final consumtion

1. Electricity is an energy carrier. It is used to carry a minor part of the energy in the world.

Critical insights

1. Electricity is an energy carrier. It is used to carry a minor part of the energy in the world.

2. Biomass is limited on a global scale. Although important in many regions, there is not enough to replace fossile fuels.

Critical insights

Renewable technologies Biomass derivedTechnologically mature with markets hydroelectric; geothermal;in at least some countries woody biomass; onshore wind

landfill gas; bioethanol; siliconsolar cells.....

Technologically mature with small, new solid waste energy in towns;markets in few countries biodiesel; offshore wind; heat

concentrating solar dishes...

Under technological development thin film PV; tidal change; wavedemonstration plants, upcoming biomass gasification; pyro-

lysis; bioethanol from ligno-cellulose; thermal towers.......

Research stageMany give electricity. All fuel technologies are based on biomass

1. Electricity is an energy carrier. It is used to carry a minor part of the energy in the world.

2. Biomass is limited on a global scale. Although important in many regions, there is not enough to replace fossile fuels.

3. Need for fuels from other renewable resources than biomass

Critical insights

!!

!!

Converted solar energy; Oil,biomass….

Electricity Solar cells ! ?

Solar fuelfor storage

Heat;Low tempHigh temp

Solar Energy, Options

12

The energy system – local versus global aspects; the place for solar energy; need for fuel

Various concepts for solar fuels

Our science in the Swedish Consortium for Artificial Photosynthesis

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Indirect

Direct methods

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Photovoltaics

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Indirect

Electrolysis→H2

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Photovoltaics

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Indirect

Electrolysis→H2

Leads to discussions about the hydrogen society

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Photovoltaics

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Indirect

Electrolysis→H2C-based fuelFrom H2 and CO2

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Biomass ConversionPyrol.,ferm., chop wood etc

Indirect

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Photosynthesis

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Indirect

Biomass Conversion

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Photovoltaics

Photosynthesis

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Indirect

Electrolysis→H2

Biomass ConversionPyrolysis, ferment., etc

C-based fuelFrom H2 and CO2

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Electricity Electrolysis

Indirect

Solar cells in Sala/Heby

Two systems -solar cells and electrolyser

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Sola

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el; h

ydro

gen

or c

arbo

n ba

sed

Indirect

Biomass,Trees; Waste;

GrassesConversion

Several systems must be integrated

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Electricity Electrolysis

Indirect

Solar cells in Sala/Heby

Biomass,Waste; Trees;

GrassesConversion

General - Extra systems costLosses in extra step(s)

Sola

r en

ergy

and

wat

erSustainable methods to make solar fuels/hydrogen

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Direct methodsSo

lar

ener

gy a

nd w

ater

Thermochemical cycles (CSP for H2)

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Direct methodsSo

lar

ener

gy a

nd w

ater

Artificial Photosynthesis in materials and nanosystems

Artificial Photosynthesis in molecular systems

Sola

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ydro

gen

or c

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n ba

sed

Direct methodsThermochemical cycles (CSP for H2)

Sola

r en

ergy

and

wat

er

e-e-D2 H2O

O2 + 4 H+ A 2 H2

4 H+

H+ H+

e- e-

P

Joining in cells

P

Artificial Photosynthesis in materials and nanosystems

Artificial Photosynthesis in molecular systems

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Direct methodsThermochemical cycles (CSP for H2)

System costs might become lower in a direct process

Sola

r en

ergy

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Semi-direct

Sola

r en

ergy

Photosynthesis(compartmentalized)

Light reactionsNADPH & ATP

Dark reactionsH2, alcohols etc

Photobiological processes – not harvesting the organism

Excreted

H2 forming heterocyst

Vegetative cells Green algae –Chlamydomonas

Can make hydrogen under special

conditionsCyanobacterium – Nostoc

Photobiological hydrogen and fuel production using living organisms.

Sola

r fu

el; h

ydro

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or c

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n ba

sed

Something in between

Mixing biological and non-biological parts

Sola

r en

ergy

PSIIPSI

H2ses Ru

Pt

HybridesEnzyme & metal catalysts

TiO2etc

Artificial Photosynthesis in materials and nanosystems

Thermochemical cycles (CSP for H2)

Photovoltaics

Artificial Photosynthesis in molecular systems

Photosynthesis

Sola

r fu

el; h

ydro

gen

or c

arbo

n ba

sed

Indirect

Direct methods

Semi-direct

Sola

r en

ergy

and

wat

er

Light reactionsNADPH & ATP

Dark reactionsH2, alcohols etc

Electrolysis→H2

Biomass ConversionPyrolysis, ferment., etc

C-based fuelFrom H2 and CO2

Photosynthesis(compartmentalized)

The energy system – local versus global aspects; the place for solar energy; need for fuel

Various concepts for solar fuels

A little on our science in the Swedish Consortium for Artificial Photosynthesis

H2

P

We follow two branches to Solar hydrogen, common link biochemistry, biophysics

H2O

H2

P

Photobiological hydrogen production in photosynthetic microorganisms

H2O

Design of organismsSynthetic biology, genomics,

metabolomics

H2O H2

P

Design and synthesisSpectroscopy

Artificial photosynthesis, synthetic light driven catalytic chemistry

MnMn

Ru

Fe

Fe

Co

Artificial photosynthesis: Target – fuel from solar energy and water!

Visionary – but how?

Artificial photosynthesis - manmade: Visionary – but how?

Idea for a short cut: Mimic (copy) principles in natural enzymes

MethodBiomimetic chemistry

Mn

PO2

O2O2

O2

? Secret of life

Element: MnAtomic weight: 55

MnMn

Mn

Four manganese atoms are the secret behind the splitting of water

O2O2

O2

Water

Photosystem II – the wunderkind in nature!

TyrZ 161 His 190

Glu 189

Asp 170

Gln 165

Ca

Water oxidation - the main players

OH

MnMnMn Mn

N

NN

N

NN

D A S H O 2 2

O 2 + e - e - 4H +

4H +

H 2 2 LinkLink

light

Ruthenium instead of chlorophyll

Supramolecular chemistrychemical LEGO

Ru

N

NN

N

NN

D A S H O 2 2

O 2 + e - e - 4H +

4H +

H 2 2 LinkLink

light

Supramolecular chemistrychemical LEGO

MnMn

Link Ru

Manganese as in Photosystem II

O

N NO NN

NN O OO

Mn Mn

Mn2(II/II) BPMP has been connected to Ru and electron acceptors

N N

N

N

N

N

EtO 2 C

NH

O

N N O N N

N N O O O

Me Me

Me

Ru

MnMn

NN

N

N

NN

NN

NNC8H17

O

O

O

O

C8H17

O

O

O

O

O NN

N N

NN

NHO

EtO2C

O OO O

3+

Ru

Mn Mn

NDI acceptor

Mw 2800

We seek catalysts based on abundant metals,

Mn-based systems have potential- The Mn4 cluster works in Photosystem II- It is the most efficient and stable part of PSII electron transfer

Co-based systems have potential- We seek molecular systems- We seek light driven systems

Cobalt as a water oxidation catalyst

Kanan and Nocera, Science 2008, 321, 5892, 1072-1075

Yin, Tan, Besson, Geletii, Musaev, Kuznetsov, Luo, Hardcastle and Hill, Science 2010, 328, 342-345

1 O2/CoON

OFF

ON

100 % light

50 % light

Co(III) oxide

PO-O

-O

PO- O

-O

Photo-driven O2 evolution with a new Co-nanoparticle

e-Co2 H2O

O2 + 4 H+ Ru

Development of a Co-ligand system for use in the split cell.

1. Link the Ru-sensitizer with ligand H4M2P (M2P for short)methyldiphosphonic acid

PPOO

HOHO OH

OH

e-Co2 H2O

O2 + 4 H+ Ru

1. Synthesized and characterized.

O

O

HO

HO

OHHO

P

P

RuN

NN

N

N

N

P

P

HO OH

HO

HO

O

O

Ru(M2P)

Development of a Co-ligand system for use in the split cell.

1. Link the Ru-sensitizer with ligand H4M2P (M2P for short)methyldiphosphonic acid

PPOO

HOHO OH

OH

+ Pi buffer+ persulfate+ light

Isolated Ru(M2P)Co 65 µg Ru(M2P)Co (ca 40 µM Ru)6 mM S2O8

2-

25 mM Pi (pH 8.4)

0 100 200 300 4000

10

20

30

40

50

O

2 (nm

ol/m

l)

Time (s)

ON

Development of a Co-ligand system for use in the split cell.

Ca 1 turnoverPhotocatalytic oxygen evolution!

e-Co2 H2O

O2 + 4 H+ Ru

1. Synthesized and characterized.2. Yes, it binds Co and the system

is photo-catalytic!

O

O

HO

HO

OHHO

P

P

RuN

NN

N

N

N

P

P

HO OH

HO

HO

O

O

Ru(M2P)

Development of a Co-ligand system for use in the split cell.

1. Link the Ru-sensitizer with ligand2. Can it bind Co and is it active?

H4M2P (M2P for short)methyldiphosphonic acid

PPOO

HOHO OH

OH

N

NN

N

NN

D A S H O 2 2

O 2 + e - e - 4H +

4H +

H 2 2 LinkLink

light

Supramolecular chemistrychemical LEGO

MnMn

Link RuCo(III) oxide

Cobolt

N

NN

N

NN

D A S H O 2 2

O 2 + e - e - 4H +

4H +

H 2 2 LinkLink

light

Supramolecular chemistrychemical LEGO

MnMn

Link Ru

Manganese like Photosystem II

Co(III) oxide

Cobolt

Hydrogenases: Enzymesthat can make and handlehydrogen S

Fe

S

Fe CN

CONC

OC

S X

NH

OC

Cys

Fe Fe

Many complexes making hydrogen!!

N

S S

Fe Fe

COCO

COOC

OC CO

Br

seconds

0 200 400 600

-12

-8

-4

0

turnovers

5

10

15

20

25

Hydrogen formation. Electrochemistry under very acidic conditions

Background

Our complex

N N Cl Cl

Aromatic dithiolate ligandsTuning for catalysis at milder potentials

Diiron complexes with aromatic dithiolate ligands

quinoxalinecarborane

NN

N

N

N

N

Ru

O O

OHHO

HO

HOFe Fe COOC

S S

OC OCCO CO

Cl Cl

1

2

3

e-

e-

4

H+

5½ H2

Ascorbic acid

Ru(bpy)32+

Fe2(μ-Cl2-bdt)(CO)6

Bimolecular approach

S S

Fe

OC CO

PMe3

RR

1: R = H2: R = Cl

Me3P

An interesting development – complexes with only one Fe can also make hydrogen.

S SFeII

Ph2P PPh2

CO

N

OO

Hydrogen at low overpotential

N

NN

N

NN

D A S H O 2 2

O 2 + e - e - 4H +

4H +

H 2 2 LinkLink

light

Supramolecular chemistrychemical LEGO

MnMn

Link RuCo(III) oxide

CoboltFe

Fe

Fe

We have water oxididation catalyst Co-nanoparticle

We have many hydrogen forming catalysts Fe-complexes

We can drive them with light!

Can we combine them?

O2 + 4H+N

NRu

NN

N

N

2-O3P

2-O3P

e-e-

2 H2O

4H+

S SFep Fed

CO CO

CN

S

OCNC

H

Cys

N[4Fe-4S]

S SH

FeI

OC CO

PMe3Me3P

S S

FeII

PR2 PR2

OC

NR

N

NPh

Ph

O

O

N

N

Ph

O

O

F2B

BF2

CoII

OR2N

NCMeX1 X2 X3

a) b) c)

N

O

O

OAr

OAr

OtBu

tBu

CO2H

ON

O

OOAr

OAr

CO2HN

O

N

O

O O

Oct

Ar =

1

2

e- e-

2 H2

e- e-

TiO2NiO

Co(III) oxide

A ”Split-cell” for complete water oxidation/fuel formation with catalysts of earth abundant elements from our laboratory

ArtificialSystems

Organisms in Bioreactors

H2 by photosynthesisWater as substrate

Soon-will work-explored by many

ArtificialSystemsBioreactors

H2 by photosynthesisWater as substrate

Soon-will work-explored by many

Long term- big potential- more unproven