CO Hydrogenation to Organic Compounds over Ni Zn ...€¦ · selectivity of Ni-Zn nanoparticles was...
Transcript of CO Hydrogenation to Organic Compounds over Ni Zn ...€¦ · selectivity of Ni-Zn nanoparticles was...
18th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
CO Hydrogenation to Organic CO Hydrogenation to Organic Compounds over NiCompounds over Ni--Zn Zn
Nanoparticles in LiquidNanoparticles in Liquid--PhasePhase
Atsushi MURAMATSUAtsushi MURAMATSU, Katsutoshi , Katsutoshi YAMAMOTO, Hideyuki TAKAHASHI, YAMAMOTO, Hideyuki TAKAHASHI,
Nobuaki SATO, and Shohei MAKIHARANobuaki SATO, and Shohei MAKIHARAInstitute of Multidisciplinary Research for Advanced Materials, Institute of Multidisciplinary Research for Advanced Materials,
Tohoku UniversityTohoku UniversityKatahira, AobaKatahira, Aoba--ku, Sendai 980ku, Sendai 980--8577, Japan8577, Japan
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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In our laboratory
Hybrid nanoparticles, nanocomposites
・Novel synthesis method.Liquid-phase reductionSelective reductive deposition in liquid phase
・Their characterization
CO hydrogenation is one of the characterization methods.Activity and product distributions→ characteristics of metal particles.
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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BackgroundCatalysts
・Novel catalyst preparation is always required.Needs and seeds (break-through)Utilization of resources
・Every-time demand to get best activities!
Nano-sized catalystBimetallic or bimetal catalyst
Activity promotionChange of selectivity and so on
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Objectives
1.Highly active Ni-Zn nanoparticles is prepared as a hydrogenation catalyst by Liquid Phase Reduction method.
2.Nanoparticle suspension is used as a CO hydrogenation catalyst. Their activities and selectivities are evaluated.
3.Laser Flash method is applied for new characterization technique for catalysts in the liquid-phase as a thermal diffusivity.
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Liquid-Phase Reduction Method
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0.01 mol/l Ni(AA)2in 2-propanol solution 50ml0.002 mol/l Zn(AA)2in 2-propanol solution 10ml
Heating(355K), 30minN2 flow(300ml/min)
0.1 mol/l NaBH4in 2-propanol 10ml
ReductionHeating(355K), 30minN2 flow(300ml/min) Hexadecane
Condensation1:Condenser2:Gas inlet3:4-neck flask 4:Stirrer5:Heating mantle6:Sample inlet
Ni-Zn nanoparticles in hexadecane
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Catalyst PreparationCatalyst Preparation
Ni(AA)2=0.005mol・dm-3 const.Zn/Ni = 0.22-propanol solution 40ml
N2 gas flow (30min, 82℃)
0.02mol・dm-3 NaBH4 10ml
2Ni2+ + BH4- → 2Ni + B3+ + 2H2
Ni-Zn nanoparticles
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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NiNi--Zn nanoparticlesZn nanoparticles
50nmφ
5nmφ
Primary particles = ca. 5nmAggregates = ca. 50 nm
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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CO hydrogenation
Reaction
High pressureCatalysts
CO + H2 Hydrocarbons, Alcoholsetc.
VentP
Standardgas
Gas chromatograph
TCD FID
Mass flow controller
Liquid-phasereactor
Gas sampler
Back-pressureregulator
Vent
By-pass
COH2N2
Ni-Zn nanoparticlesin hexadecane 50ml
Temp.→573 KPressure→1.5 MpaStir → 300 rpm
CO,H2
Reaction 12 h
Analysis
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Reaction conditions
H2 COCase 1 0 7.5 7.5Case 2 0.005 7.5 7.5Case 3 0.0075 10.2 10.2Case 4 0.01 15.0 15.0Case 5 0.02 30.0 30.0Case 6 0.05 75.0 75.0Case 7 0.1 150.0 150.0
Flow rate /ml / minNi content/mol / l
Reaction temperature : 573 KReaction pressure : 1.5 MPaRevolving speed : 300 rpmW/F(catalyst weight/flow rate) : 29.1 g-cat h / molZn/Ni : 0.2
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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0 2 4 6 8 10 120
10
20
30
40
50
60
70
CO
con
vers
ion
/ %
Reaction time / h
Ni content mol / l 0 mol / l 0.005 mol / l 0.0075 mol / l 0.01 mol / l 0.02 mol / l 0.05 mol / l 0.1 mol / l
Change in CO conversion
0.005~0.01 mol/l -> active
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Distribution 6 h
methane ethane ethylene propane butane CO2
0.005 38.4 3.7 0.5 1.0 1.5 38.90.0075 38.3 2.5 0.2 0.7 2.1 38.9
0.01 41.8 2.8 0.1 0.3 0.5 42.20.02 34.9 3.2 0.8 1.0 0.5 37.00.05 42.5 0.9 0.1 0.1 0.4 50.20.1 50.5 1.0 0.0 0.0 0.2 44.0
Selectivity / %Ni contentmol/l
methanol ethanol acetone 1-propanol 2-propanol0.005 12.2 1.4 0.7 1.3 0.4
0.0075 11.6 1.3 0.6 1.8 1.90.01 11.2 0.2 0.0 0.1 0.00.02 5.1 1.5 8.9 0.0 7.00.05 3.0 0.3 0.2 0.4 0.20.1 2.2 0.6 0.1 0.2 0.1
Selectivity / %Ni contentmol/l
CH4、CO2、CH3OH were formed.0.005~0.01 mol/l -> high selectivity to methanol
Active in oxygenate production
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Used Ni-Zn nanoparticles
Ni-Zn nanoparticles・high activity・life time
Methanol synthesis
Ni content : 0.01 mol/l (Zn/Ni=0.2)
5~20nm nanoparticles
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Laser Flash method
L
Pulse laser
Sample
Detector
Short measurement timeNo contact with specimen
Obtaining adiabatic stateNegligible for convection
t1/2
T1/2
Tmin
Tmax
Tem
pera
ture
res
pons
e
Time , t / s
2/1
2
1388.0tL
×=α
α : Thermal diffusivity [mm2/s]
(α = λ / Cp ρ)
L : thickness [mm]
t1/2 methodTemp. response of back side
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Cell design
To measure thermal diffusivity of a liquid under atmospheric conditions
Features
O -ri ngT eflo n s pac erA cry lic tub eC u p lat eB k7 win do w C aFw in dow
L ase r
p um pS am ple
2
Cutu be
O -ri ngT eflo n s pac erA cry lic tub eC u p lat eB k7 win do w C aFw in dow
L ase r
p um pS am ple
2
Cutu be
O-ringSpacer
Acrylic tube
Cu plateBk7 window
CaFwindow
Laser
Rotarypump
Sample
2
Cutube
1. Materials are necessary to absorb laser beam and to emit infrared light.
2. Caloric leak is limited.3. Light path is limited below
0.5mm.4. Impurities should be
avoided.5. One-dimensional heat
transmission is needed.
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Outline of Laser Flash Apparatus
Sample cell
InSbInfrared detector
Alconcavemirror
Rotary pump
Radiation
Dark room
Concavelens
Pulse ruby laser
Watercooler
AMP
FilterOscilloscopePC
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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0.00
0.03
0.06
0.09
0.12
0.15
0.18
hexane
toluene
1-propanol
ethanol
2-propanol
water
Th
erm
al d
iffus
ivity
, α
/ m
m2 /s
Sample
Measured value Literature value
0.00 0.02 0.04 0.06 0.08 0.100.050
0.055
0.060
0.065
0.070
0.075
Ther
mal
diff
usiv
ity ,
α /
mm
2 /s
Ni content / mol/l
Results
Consistent with literature
Success in precise measurement of a liquid
・With increasing Ni-Zn particle amount, thermal diffusivity was increased linearly.・9 % increase was found for 0.1 mol/l particle suspension.
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Summary1. Ni-Zn bimetallic nanoparticles were prepared by liquid-phase
reduction method.2. They were found active for methanol synthesis in CO
hydrogenation.3. Even though the same contact time was chosen, the activity and
selectivity of Ni-Zn nanoparticles was changed.4. Thermal diffusivity of nanoparticle suspension was increased
with increasing particle concentration.5. Laser flash method to measure the thermal diffusivity was useful
as a novel characterization technique for suspension catalysts.6. Unfortunately the explanation of the solid concentration effect
due to the thermal diffusivity was failed.
8th Japan-China Symposium on Coal and C1 Chemistry
Dec. 10, 2004, Kitakyushu, Japan
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Next stage of this study1. Try to explain the solid concentration effect by the stability
of the suspension.Dispersion and aggregation of particles
2. Promote the stability of Ni-Zn nanoparticles.Selective deposition of Ni-Zn onto TiO2 nanoparticles
3. Enhance the activity and selectivity to oxygenates.Use of the adequate additives
4. Generalize the Laser Flash method.