nanotechnology in catalysis... · 2011. 1. 3. · nanotechnology in catalysis. nsf workshop...
TRANSCRIPT
Nanotechnology In CatalysisA Decade of Progress and Into the Future
S. Mark Davisat NSF Grantees Conference
on NSE, Dec. 6-8, 2010
Nanotechnology In Catalysis
NSF Workshop 2003—M.E. Davis, T.D. Tilley, et.al.WTEC Follow-On Study 2007—R.J. Davis et.al.
• Grand Challenge: Control composition and structure over length scales from 1 nanometer to 1 micron to provide catalytic materials that accurately and efficiently control reaction pathways
– Catalysts are engines that power the world at the nanometer scale– Catalysts are the most successful application of nanotechnology– Technologies contribute to ~ 1 T$ revenue in US and ~30% of GDP
Nanocatalysis Is The “Science Of Synthesis And In-situ Characterization OfSupramolecular Materials….It Differs From Traditional Catalysis Since The Materials Are Explicitly Designed Over Length Scales Larger Than Single
Active Sites”...... R. Schlogl, S. Hamid; Angew. Chem. Int. (2004)
~ 880 Million
Gallons Per Day (World Wide)
3.2 Billion 1.9 Billion
Crude Production
Refining & Chemicals Fuel
Gasoline
Diesel/Gasoil
~ 980 MillionToday’s Infrastructure• Massive• Global• Highly Efficient• 100 Years in Making
Large and Complex Industry
~ 300-400 MillionChemicals
• Energy Efficiency • New Economies on the Rise• Integration of Energy Networks• Environmental Regulations
• Crude Quality• Sources
Production
• CO2 Mgmt.• Reduced Emissions
Refining& Chemicals
• Reduced Emissions
• Adv. ICEs
Vehicles
• Molecularly Tailored Fuels
Fuels
Agents of Change
Catalytic Material Challenges
HA
C9
C6
+ H++
.
+
+
H+ +
H+ +
H+ + A-
.
• Mesoporous and multifunction materials • Poison resistant metals and metal compound catalysts• Shape selective catalysts for fuels and chemicals• Pore system design to optimize mass transport vs kinetics
Tailored Structure and Structure/Property Control at Nanoscale Critical for Next Generation Catalysts
High Throughput R&D Improving Technology Delivery
REFINING
SCANFiningTM
ULS Diesel
NebulaTM
MSDWTM
MAXSATTM
EMOGASTM
CHEMICALS
XyMaxSM
PxMaxSM
TransPlusSM
EBMaxSM
Cumene
OLGONESM
Advanced Catalyst Technology
Kinetics & Models
AdvancedCharacterization
Catalyst / Process Scale-up
HTE Synthesis & Testing
60Å
100Å
20Å
40Å
Zeolite YZSM-5
Pore Size A
406080100
5
10
20
MCM-41
Gasoil ResidsGasolineChemicals
°
Shape Selective Catalysis Key to Managing Molecular Size & Shape
• MCM-41 Recent Commercial Nanotechnology Example
Aromatics
FCC
Surfactant Micelle
Micelle RodHexagonal Array
Calcination
MCM-41
Silicate
MCM-41: Early Example of Self Assembly
Clad the Surface
Vary Chemical
Composition
Vary Pore Size1.5nm to >10nm
Anchor Metalsand Catalysts
Many Options for Tailoring Microstructure
and Reactivity
Lube Dewaxing: Shape-Selectivity in Action
• EM Hydroisomerization Technology Is Industry’s Most Selective, Highest Yield Lubricant Dewaxing Technology
Wax Molecule
Bulky LubricantMolecule
Large Molecule Cannot Enter Zeolite Pore
Unchanged Bulky Lubricant Molecule
Lubricant Molecule
Tailored 1-d Zeolite Catalyst
Go
• New Form Of Shape Selectivity• EB Production Using MCM-22
– Structural Features» 12-R cavities (A) via
10-ring windows (B)» 12-R surface pockets (D)
• Alkylation Occurs In Surface Pockets• Multiple Alkylation In Cages Avoided
“ Surface Pocket Catalysis”
D
D+
Recent Commercial Applications
Topsoe BRIMTM Diesel HDS Catalysts• R&D enhanced by fundamentals understanding • Promoted MoS2 crystallites have 1-D metallic
“brim” states that contribute to activity
STM image3 nm MoS2
Univ. Aarhus
Topsoe FENCETM Catalysts forMethanol Synthesis
• Higher activity and longer lifetime• Cu-sintering inhibited by “picket fence” • Cu/ZnO interaction stabilizes copper • ZnO separation by Al203 provides barrier
Images Reproduced with Permission of Haldor Topsoe Inc.
Recent Commercial Applications
NxCatTM System for Naphtha Reforming• Hexagonal Pt(111) favors
aromatics—Davis, Somorjai • High area catalyst developed/demonstrated
2008—Zhou et.al., Headwaters
NxCatTM for Direct HydrogenPeroxide Synthesis
• Uniform 4 nm PtPd particles• (110) structure gives selectivity• Commercial demonstration by
Headwaters/Evonik • 2007 EPA Green Chemistry Award
Images Reproduced with Permission of Headwaters Inc.
National Lab Activities
Raft Structures on Alumina • Peden, et.al. (PNNL/ORNL); Science (2009)• High field NMR and STEM enables unique
probing of metal support interaction• PtO rafts anchor to “penta-coordinate”
aluminum sites
New Synthesis Methods for Nano-particles• Nenoff et.al. (SNL); J.Phys Chem. C (2009)• Photo-reduction produces homogeneous alloy
nano-particles in normally immiscible systems• Complements “core-shell” systems
HRTEM--AgNi 50/50
Images Reproduced with Permission of Authors.
New Science—Future Platforms??
Tailored Emulsions for PhaseTransfer Catalysis
• D. Resasco et.al.; Science (2010)• Pd/CNT/oxide nanoparticles stabilize
emulsions, do catalysis at interface• Simplified biofuels processing
Energy Conversion Based on Catalysis• Hot electrons generated in catalyzed
reactions can be converted to currentin nano-diode structures
• Somorjai, et.al.; JACS (2005)
Images Reproduced with Permission of Authors.
New Science—Future Platforms??
Selective Syngas Conversion to Ethanol• X. Bao et.al.(DICP); Nature Materials (2007)• RhMn particles inside nanotubes 10x more
active than particles outside • Host-guest electronic interaction??
Highly Selective Epoxidation• Tilley, Ruddy; JACS (2008)• Single site tantalum alkoxide
species in mesoporous silicagive 99% epoxide selectivity
• Ta(η2-O2) intermediate
MesoporousSBA15 Silica
Images Reproduced with Permission of Authors.
Structure Control in Powders and Pellets
Non Classical Synthesis and New Fabrication Methods: New precursors, metastable structures, structure directing methods Control particle size, shape, and surface structure
Morphology and Distribution: Placement of active species, promoters in specific environments Pore system design
Modifying Site Functionality: Acid site strength and density, promoters, multifunction systems
Advanced Characterization and Chemistry Fundamentals:
....
....
Lessons Learned
• Breakthrough Discovery Isn’t Easy
• Cost Effective Development andCommercialization Is Harder
• Partnerships, High Throughput Methods, and Modeling Are Decreasing CycleTimes to Commercialization
• Coupling Nanotechnology Developers withApplications Developers is Essential- Universities and National Laboratories- Spin-off companies- Established technology suppliers
Significant Recent Progress—Promising Future Potential