HYDROGEN – A FUEL OF THE FUTURE AND MORE: Challenges and problems

Paolo FORNASIERO

Workshop on Material Challenges in Devices for Fuel Solar Production and Employment, Trieste, May 20, 2014

Energy and quality of life

2011Energy consumption

2011Human development index

The end of the cheap oil

Global density of pollution

DangerDangerDangerDanger

CrisisCrisisCrisisCrisis

OpportunityOpportunityOpportunityOpportunity

Hydrogen : motivation

DOE State of the States: Fuel Cells in America 2014

Darwin on the road

4Q 2013 Navigant Research

Consumption : future trends

6000 fuel cell vehicles

$385 million investment

Tokyo 2020 : Hydrogen Town

H4

Snímka 9

H4 After the Tokyo Olympics are over, the electricity and hot water generated with hydrogen energy are expected to be furnished to a school, and commercial and other facilities to be constructed on the village site. The plan is set to be the largest experiment employing the new energy source. The Tokyo government hopes to take advantage of the 2020 Olympics as an opportunity to advance the realization of a society based on hydrogen energy.Hydrogen filling stations and pipes around the village will be constructed. Fuel cells installed at each station will generate electricity and heat through the reaction of hydrogen and oxygen in the air. Buses will also run on fuel cells.About 17,000 athletes and other guests will stay in the Athletes’ Village.Hp; 19. 3. 2015

California Fuel Cell Partnership. 2014 Update: Hydrogen Progress, Priorities and Opportunities (HyPPO) Report

23 stations operating in California in 2015 68 stations in 2018-2019

H2 stations : California case

Large reformer H2 vehicle

NG H2

Large reformer Truck Delivery

C-H2

Refuelling stationDewar

Pump dispenser

compressed H2

H2 vehicle

compressed H2

Electrolyser compressor storage dispenser

H2 vehicle

compressed H2

On-line reformer compressor storage dispenser

NG

Large reformer

H2

Pipeline Delivery

H2 vehicle

compressed H2

compressor storage dispenser

Truck Delivery Dewar

L-H2NG H2

H2 vehicle

liquid H2

dispenser

H2 economy : Infrastructures requirements

New distribution systems (technical requirements and costs)

H2 storage systemsCompressed Gas Storage Tanks

(Heavy and space / safety concern)

Metal hydrides(Heavy, performance)

Hydrogen vehicles: technical requirement

Possibility of H2 storage in SWCN (up to 67 wt %)A.C. Dillon et al. Nature 386 (1997) 377.

A.Chambers et al. J. Phys.Chem. B 102 (1998) 4253.

H2O / H2 storage in carbon nanofibers (< 2 wt%) R.T Yang et al. Carbon 38 (2000) 623.

Omar M. Yaghi et co-workers, SCIENCE VOL 300 16 MAY 2003

Hydrogen Storage in MicroporousMetal-Organic Frameworks (MOFs)

Zn4O(BDC)3 (BDC 1,4-benzenedicarboxylate)

Hydrogen storage – on board

Taken from B. C. H. Steele & A. Heinzel, Nature, 414 (2001) 345

Fuel Cells

H2 production

from

fossil fuels

Steam Reforming

Partial Oxidation

Autothermal Reforming

Today: Steam Reforming

�High metal loading(until 15% wt)

�High coking deposition(catalyst deactivation)

�High operative temperature(highly endothermic reaction, 600-900 °C)

Ni basedCatalyst

Hydrocarbons nCOHm

nOnHHC mn ++→+ 22 )2

(

e.g. Methane

TEM pictureI. Alstrup, Haldor Topsøe A/S.

Catalyst deactivation:C filament formation

H2O

CO, CO2,H2

FuelAirH2O

CO, H2CO2, H2,H2O

Reformer

Fuel Cell

WGSR PROX

miniaturization technology

O2

On board H2 production

Catalyst Design: Pd@CeO2 system

Science 309 (2005) 752

Science 341 (2013) 771

Science 337 (2012) 713

Cs

Ru

CNTs

Ru

Graphitized-CNTs

Ru

Graphitized-CNTs

Conductive support + promoter + Ru

LOW T ACTIVITY!

Storage

H2 production

FC utilization

180°C

90°C

A. K. Hill et al., Applied Catalysis B: Environmental, 172-173, 2015,129–135

Hydrogen from ammonia

Partial Oxidation

nCOHm

On

HC mn +→+ 22 22

Alternative reaction route

� is mildly exothermic and is much more energy efficient;

� a smaller reactor can be used to achieve high CH4conversion and selectivities to CO and H2 with short contact time;

� no need for large amounts of expensive superheated steam

It may be carried out with a much broader range of compounds, from Natural Gas to heavy residues and even coal

Autothermal Reforming

Alternative reaction route

22224 eCOdCOcHbOOaHCH ++→++

Its main benefit lies in compensating for the endothermic reaction of Steam Reforming with the exothermic reaction of Partial Oxidation

�no extra heating�no extra cooling

e.g. Methane

It is probably the most interesting among coming developmentsin H2 production processes from hydrocarbons.

Water splitting in 2 steps:

Oxygen from reducible oxide exposed to concentrated sun light

Hydrogen from water reduction at lower temperature, via oxidation of reduced oxide.

1

2

1

2

Perovskites

DOE target, still difficult to reach:26% Solar to Hydrogen (STH) efficiency

Multiple reduction chamber

Overcome pumping problemsto diminish O2 pressure

http://www.hydrogen.energy.gov/pdfs/progress14/ii_c_2_mcdaniel_2014.pdf

H2 production

from

renewable resource

Steam Reforming of alcohols

Aqueous Phase Reforming

Photocatalytic H 2O splitting

Methanol

Ethylene Glycol

Glycerol

Sugars (Glucose) (Xylose)

Sugar Alcohols(Sorbitol)

Liquid-Phase Reforming

Single Reactor System

Low Temperature

160 – 265 oC

Relatively Low Pressure

Less Than 68 bar

Simple Vapor-Liquid Separator

Hydrogen-Rich GasLess than 100 ppm CO

Liquid-Water

Aqueous-Phase Reforming

(APR) Process

�Eliminates Energy required to vaporize water�Allows processing bioproducts that cannot be vaporized without decomposition�Compatible with processing wet feedstocks, avoiding need for an initial dehydration step�Operates at low T compared with conventional reforming, reducing energy costs�Water gas shift reaction occurs simultaneously with reforming�Pressurized product is compatible with membrane or p swing H2purification

Glycerol reforming on

Pt-supported catalysts

R.R.Soares et al., Angew.Chem.Int.Ed. 45(2006)3983

COHHOC 34 2833 +→

Photocatalytic H2 production

Fujishima A, Honda K (1972) Nature 238:37Renewable and Sustainable Energy Reviews 11 (2007) 401-425Topics in Catalysis 49 (2008) 4-17

TiO2 nanocrystals for photo-assisted H2 production

J. Am. Chem. Soc 134 (2012), 6751–6761

% {001} % {101}

4.5 95.5

26.6 73.4

54.3 45.7

TiO2 nanocrystals for photo-assisted H2 production

P. Fornasiero et al., J. Am. Chem. Soc 134 (2012), 6751–6761

high volumes of hydrogen (up to 2.1 mmol h–1 g–1) under simulated solar illumination.

The {101} facets of anatase are more active than the {001}.

TiO2 nanocrystals for photo-assisted H2 production

J. Am. Chem. Soc 134 (2012), 6751–6761

3D TNTA supported Pd NPs preparation and application

60V 10min 60V 60min 60V 180min

3.2- 3.5 µµµµm 4.2- 4.7 µµµµm1.5- 1.8 µµµµm

Anodrization solution: NH 4F + Ethylene Glycol

Ti Anode

Ti Cathode

CBA

FED

2D TiO2 nanotube arrays (TNTA) substrate supported Pd NPs

32

The ElectroChemical Milling and Faceting process

Angew. Chem. Int. Ed., 2012, 51, 8500

HRTEM analysis of the Pd/TNTA disk electrode

Angew. Chem. Int. Ed., 2012, 51, 8500

� The evolution of gases from a water/ethanol solution upon si mulated sunlightirradiation for different typs TiO 2 nanotube array catalysts. (EtOH 50%, 80ml,150WXe lamp, 180mW cm -2)

Blue line: 3D TNTAs-web + 0.1mg/cm 2 Pd. Green line: 3D TNTAs-web withoutPd.

Red line: Flat TNTAs + 0.1mg/cm 2 Pd. Black line: Flat TNTAs without Pd.

Photoassisted H2 generation from EtOH solution

R. M. N. Yerga , M. C. A. Galván , F. del Valle , J. A. V. de la Mano , J. L. G. Fierro, ChemSusChem 2009 , 2 , 471

Band position relative to water redox potential

Fe2O3 polymorphs for photo-assisted H2 production

Solar-to-Fuel Efficiency

0.16%

0.86%

0.48%

Advanced Functional Materials 2014

Au and Ag on εεεε-Fe2O3 polymorphs for photo-assisted H2

production

40

30

20

10

0

H2

Evo

lutio

n (µ

mol

/cm

2 )

24201612840Irradiation time (h)

Au/Fe2O3

Ag/Fe2O3

Fe2O3

NH2

NH2

+O

HN

N

Conventional synthesis:

Very toxic andcarcinogenic

� T = 100 – 200 °C

� Strong acidic conditions

� Strong oxidants

Synthesis of benzimidazole

NH2

NH2

+O

HN

N

Conventional synthesis:

Very toxic andcarcinogenic

� T = 100 – 200 °C

� Strong acidic conditions

� Strong oxidants

Synthesis of benzimidazole

Alternative processes:

� Less toxic reagents

� Renewable and cheap solvent

[H]ads

hν, cat

Synthesis of benzimidazole

29/03/2015 41

Potential Environmental Impact of a Hydrogen Economy on the StratosphereTromp T.K. et al. Science 300 (2003), 1740

Latitudinal and seasonal distribution of column ozone depletion (%) due to an assumed fourfold increase in H2, simulated by the Calteh/JPL 2-D model