1 Unité de catalyse et de chimie des matériaux divisés, Université catholique de Louvain
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1 Unité de catalyse et de chimie des matériaux divisés, Université catholique de Louvain Croix du Sud 2/17, 1348 Louvain-la-Neuve (Belgium) – * [email protected] ; FNRS Research Fellow An innovative preparation of heterogeneous metal nanoparticles catalysts for VOC abatement: the onion-type multilamellar vesicles route [1] D.P. Debecker 1 *, C. Faure 2 , M.-E. Meyre 2 , A. Derré 2 and E.M. Gaigneaux 1 2 Centre de Recherche Paul Pacal (CNRS), Université de Bordeau 1 Avenue du Dr. Albert Schweitzer, 33600 Pessac, France www.emmimaterials.e u CONCLUSION 1. Transfer of onion-grown Ag nanoparticles onto an inorganic support: easy and quantitative 2. In situ burning of the surfactant leads to: accessible catalyst surface and active catalyst 3. Relative stability vs. sintering 4. Potential application with nanoparticles of various nature, form, size, density, etc Ti Ag C V ӨAgT_D 15.3 2.1 46.7 na ӨAgT_E 19.1 0.1 39.1 na ӨAgTV_E 15.8 0.2 38.0 3. 1 376 374 372 370 368 366 364 B inding Energy (eV) TiO 2 (%) Ag (%) V 2 O 5 (%) Mass balance (%) ӨAgT_D measure d 90.4 5.1 - 4.5 Expecte d 91.1 4.3 - 4.6 ӨAgT_E Measure d 96.4 0.3 - 3.4 Expecte d 95.0 0.2 - 4.8 ӨAgTV_E Measure d 90.7 0.3 4.0 4.9 Expecte d 90.0 0.3 4.3 5.4 50 150 250 350 450 Tem perature (°C ) W eightloss derivative (a.u.) - Ti (%) Ag (%) C (%) O (%) N (%) Ag/ Ti C/ Ti N/ Ti ӨAgT_D 15.3 2.1 47 34 2.0 0.14 3.0 0.1 3 ӨAgT_D Calcined 21.6 5.1 26 47 0.4 0.24 1.2 0.0 2 [1] D.P. Debecker et al., Small, In Press [2] S. Eriksson et al. Appl. Catal., A 265 (2004) 207 [3] C. Faure, et al. J. Phys. Chem.107 (2003) 4738 Adherence, accessibility, activity and stability of supported Ag nanoparticles Quantitative transfer of Onion-grown Ag nanoparticles onto TiO 2 support (‘T’) and V 2 O 5 /TiO 2 (‘TV’) catalyst. surfactant + water is sheared in vials with a spatula to form onions. AgNO 3 is introduced by encapsulation (at the shearing step, denoted ‘E’) or by diffusion into preformed onions (denoted ‘D’) TEM: aggregate of Ag nanoparticles-loaded onions Chemical analysis (ICP-AES) XPS surface analysis Most of the surfactant is burned out at ~320°C Small particles still adhere on TiO2 after calcination Surface C and N (from the surfactant) concentrations drop Ti, O, Ag concentrations increase (accessibility of inorganic surface) 0 10 20 30 40 50 250 300 350 400 Tem perature (°C ) Benzene conversion (% ) - T O AgT H40m (1) O AgT H40m (2) 0 20 40 60 80 100 250 300 350 400 Tem perature (°C ) B enzene conversion (% ) - TV O AgTV (1) O AgTV (2) TG analysis of Ag nanoparticle loaded onion TEM: Ag nanoparticles grown in onions and impregnated on TiO 2 particles After incubation After impregnation Left: diffusion (D) ~10 nm Right: encapsulation (E) ~5 nm XPS surface analysis High carbon surface concentration Excess of Ag in ‘D’ preparation Low Ag load in ‘E’’ preparation XPS: Ag 3d peak Experimental composition closely fits the expected values The surfactant account for less than 5% of the total dry weight After calcination (320°C, air) TEM: calcined catalyst Activity measurements in benzene total oxidation (C 6 H 6 :O 2 100ppm:20% in He ; 200 ml/min ; 200 mg of catalyst in fixed bed reactor TiO 2 (T) = poorly active AgT catalyst: First run <350°C: less active (surfactant covering ; inaccessible surface >300°C: increase of activity (Ag nanoparticles work in the reaction) AgT catalyst: Second run Accessible surface ; (smaller) effect of Ag from 350°C. V 2 O 5 /TiO 2 (TV) = very active VOC catalyst AgTV catalyst: First run <300°C: less active (surfactant covering ; inaccessible surface 300-400°C: total conversion : no effect of Ag AgTV catalyst: Second run Accessible surface ; synergistic effect between V 2 O 5 and Ag at 250°C Activity measurements in benzene total oxidation (C 6 H 6 :O 2 100ppm:20% in He ; 200 ml/min ; 200 mg of catalyst in fixed bed reactor RESULTS INTRODUCTION Chemical reactions demand metal-based catalysts with small, stable and tailored nanoparticles [2] industrial and fundamental interest Limitation of classical preparation method: need of thermal treatment during which sintering is hardly controlled deactivation, loss of selectivity, etc. [2] Production of tailored metal nanoparticle at ambient t° inside organic onion-type vesicles [3] used in the preparation of solid catalysts ! Interest Constraint New idea STRATEGY
description
An innovative preparation of heterogeneous metal nanoparticles catalysts for VOC abatement: the onion-type multilamellar vesicles route [1]. D.P. Debecker 1 *, C. Faure 2 , M.-E. Meyre 2 , A. Derré 2 and E.M. Gaigneaux 1. - PowerPoint PPT Presentation
Transcript of 1 Unité de catalyse et de chimie des matériaux divisés, Université catholique de Louvain
1 Unité de catalyse et de chimie des matériaux divisés, Université catholique de Louvain Croix du Sud 2/17, 1348 Louvain-la-Neuve (Belgium) – * [email protected] ; FNRS Research Fellow
An innovative preparation of heterogeneous metal nanoparticles catalysts for VOC abatement: the onion-type multilamellar vesicles route[1]
D.P. Debecker1*, C. Faure2, M.-E. Meyre2, A. Derré2 and E.M. Gaigneaux1
2 Centre de Recherche Paul Pacal (CNRS), Université de Bordeau 1 Avenue du Dr. Albert Schweitzer, 33600 Pessac, France www.emmimaterials.eu
CONCLUSION1. Transfer of onion-grown Ag nanoparticles onto an inorganic support:
easy and quantitative2. In situ burning of the surfactant leads to:
accessible catalyst surface and active catalyst3. Relative stability vs. sintering4. Potential application with nanoparticles of
various nature, form, size, density, etc
Ti Ag C V
ӨAgT_D 15.3 2.1 46.7 na
ӨAgT_E 19.1 0.1 39.1 na
ӨAgTV_E 15.8 0.2 38.0 3.1
Université c atholique de Louvain (Belgium) - Té l +32 (0)10 47 36 64 - P rinted using Ca saXPS
376 374 372 370 368 366 364
Binding Energy (eV)
TiO2 (%) Ag (%) V2O5 (%) Mass balance (%)
ӨAgT_D measured 90.4 5.1 - 4.5
Expected 91.1 4.3 - 4.6
ӨAgT_E Measured 96.4 0.3 - 3.4
Expected 95.0 0.2 - 4.8
ӨAgTV_E Measured 90.7 0.3 4.0 4.9
Expected 90.0 0.3 4.3 5.4
50 150 250 350 450
Temperature (°C)
We
igh
t lo
ss d
eri
vativ
e (
a.u
.) -
Ti (%) Ag (%) C (%) O (%) N (%) Ag/Ti C/Ti N/Ti
ӨAgT_D 15.3 2.1 47 34 2.0 0.14 3.0 0.13
ӨAgT_D Calcined 21.6 5.1 26 47 0.4 0.24 1.2 0.02
[1] D.P. Debecker et al., Small, In Press [2] S. Eriksson et al. Appl. Catal., A 265 (2004) 207 [3] C. Faure, et al. J. Phys. Chem.107 (2003) 4738
Adherence, accessibility, activity and stability of supported Ag nanoparticles
Quantitative transfer of Onion-grown Ag nanoparticles onto TiO2 support (‘T’) and V2O5/TiO2 (‘TV’) catalyst.
surfactant + water is sheared in vials with a spatula to form onions.AgNO3 is introduced by encapsulation (at the shearing step, denoted ‘E’) or by diffusion into preformed onions (denoted ‘D’)
TEM: aggregate of Ag nanoparticles-loaded onions
Chemical analysis (ICP-AES)
XPS surface analysis
Most of the surfactant is burned out at ~320°CSmall particles still adhere on TiO2 after calcination
Surface C and N (from the surfactant) concentrations dropTi, O, Ag concentrations increase (accessibility of inorganic surface)
0
10
20
30
40
50
250 300 350 400
Temperature (°C)
Ben
zene
con
vers
ion
(%)
-
T
OAgT H40m (1)
OAgT H40m (2)
0
20
40
60
80
100
250 300 350 400
Temperature (°C)
Be
nze
ne
co
nve
rsio
n (
%)
-
TV
OAgTV (1)
OAgTV (2)
TG analysis of Ag nanoparticle loaded onion
TEM: Ag nanoparticles grown in onions and impregnated on TiO2 particles
After incubation After impregnation Left: diffusion (D)~10 nmRight: encapsulation (E)~5 nm
XPS surface analysis
High carbon surface concentrationExcess of Ag in ‘D’ preparationLow Ag load in ‘E’’ preparation
XPS: Ag 3d peak
Experimental composition closely fits the expected valuesThe surfactant account for less than 5% of the total dry weight
After calcination (320°C, air)
TEM: calcined catalyst
Activity measurements in benzene total oxidation (C6H6:O2 100ppm:20% in He ; 200 ml/min ; 200 mg of catalyst in fixed bed reactor
TiO2 (T) = poorly activeAgT catalyst: First run <350°C: less active (surfactant covering ; inaccessible surface>300°C: increase of activity (Ag nanoparticles work in the reaction) AgT catalyst: Second runAccessible surface ; (smaller) effect of Ag from 350°C.
V2O5/TiO2 (TV) = very active VOC catalystAgTV catalyst: First run <300°C: less active (surfactant covering ; inaccessible surface300-400°C: total conversion : no effect of Ag AgTV catalyst: Second runAccessible surface ; synergistic effect between V2O5 and Ag at 250°C Activity measurements in benzene total oxidation
(C6H6:O2 100ppm:20% in He ; 200 ml/min ; 200 mg of catalyst in fixed bed reactor
RESULTS
INTRODUCTION
Chemical reactions demand metal-based catalysts with small, stable and tailored nanoparticles[2]
industrial and fundamental interest
Limitation of classical preparation method: need of thermal treatment during which sintering is hardly controlled
deactivation, loss of selectivity, etc.[2]
Production of tailored metal nanoparticle at ambient t° inside organic onion-type vesicles[3]
used in the preparation of solid catalysts !
Interest
Constraint
New idea
STRATEGY
