Nickel based bimetallic catalysts supported
on titania for selective hydrogenation of
cinnamaldehyde
Presented by
M. G. PRAKASH
National Centre for Catalysis Research
Indian Institute of Technology, Madras
Introduction
 Bimetallic catalysts - composed of two metal elements in either alloy or intermetallic
form often develop as materials of new category with catalytic properties different
from monometallic catalysts.
 Generally bimetallic alloys in particular , is an import subject for a number of
technological reasons some of which are
(1) Catalyst Chemistry (2) Electrochemistry (3) Metal-Metal Interfaces (4) Microelectronic
Fabrication etc.
The following aspect of an alloy surface should be examined ,
1) The chemical composition of an alloy surface
2) The surface structure factor
3) The electronic structure and geometric factors
Fig A hypothetical situation of (100) surfaces of an alloy XY with the fcc structure
(a) Pure X (b) 50 % X , 50 % Y , ordered (C) 50 % X, 50% Y with Clustering of Y
(d)75% X,25 % Y
Nieuwenhuys, The chemical physics of Solid Surface Amsterdam 1993, 6 185-22
Schematic illustration of producing crown jewels structure
X.Liu, D. Wang and Y.Li Nano Today(2012) ,7 448-466
Objectives
 To prepare Nickel Nano particles by using green chemistry via glucose as
reducing agent, supported on P25 .
 Preparation of bi-metallic Ni-Cu/TiO2, Ni-Ag/TiO2 and Ni-Au/TiO2 catalysts.
Optimization of the reduction conditions for the prepared catalysts.
 Studying the Physico-chemical properties of the catalyst samples using various
techniques like XRD, TPR, TEM etc.
 Studying the catalytic activity of the reduced catalysts using model reactions,
liquid phase hydrogenation of cinnamaldehyde.
 Identifying the reaction products using GC.
 Establishing correlations between the activity, stability and selectivity of the
catalysts and their Physico-chemical properties .
Olefinic group
Reaction scheme
Carbonyl group
G = 118 KJ/mol
undesired rex
Desired rex
G = 80.71KJ/mol Desired product
undesired rex
G = 37.79 KJ/mol
G = 0.49KJ/mol
CAL=cinnamaldehyde, COL=cinnamyl alcohol, HCAL= hydrocinnamaldehyde,
HCOL=hydrocinnamyl alcohol
6
Aim and scope of the work
Experimental approach
To prepare, characterize and test performance of following catalysts
1)
•
•
•
Influence of preparation Methods (Bimetallic catalysts)
Direct Impregnation Method
Urea Deposition method
Impregnation of stabilzed Ni Nano particles
(a)hydrazine hydrate (b) glucose (green chemistry)
Preparation of Bimetallic Cataslyst
0.03 moles of Nickel acetate + 0.03 moles of Cu or Ag or Au +
40 ml of D-glucose solution (0.1 M)
Stirred for 30 min at RT
10ml of liq.ammonia solution
Refluxed for 5 h at 80⁰ C
The solution was changed black colour
1g of TiO2 ( P25)
Stirred for 2 h at 80⁰ C
Cooled , centrifuged and dried at 60⁰ C
M .Vaseema,N.Tripathya G. Khangbandb Y.Hahn*aRSC Adv., 2013, 3, 9698–9704
Fig .1 shows the XRD patterns of (a) Ni/P25 (b) Ni-Cu/P25 (c)Ni-Ag/P25
(d)Ni-Au/P25
Fig .2 shows the TPR profile of (a) Ni/P25 (b)Ni-Cu/P25 (c)Ni-Ag/P25 (d)Ni-Au/P25
Fig .3 shows the TEM Images are (a) Ni/P25 (b)Ni-Cu/P25 (c)NiAg/P25 (d)Ni-Au/P25
Fig.4Hydrogenation of cinnamaldehyde on Ni/P25 ,Ni-Cu/P25,Ni-Ag/P25and
Ni-Au/P25 conversion and selectivity. Reaction temperature 373 K ,Time 1 h
,catalyst 150 mg, cinnamaldehyde 1.2 g reactant.
Table.1. Hydrogenation of cinnamaldehyde on Ni and Ni based bimetallic
catalysts on TiO2 supports at different temperatures
Selectivity (%)
No
Catalysts
CAL Conv. %
1
Ni/ P25-100º C
Ni/ P25-120º C
Ni/ P25-140º C
HCAL
COL
HCOL
others
60.0
91.0
98.0
63.0
31.0
29.0
31.0
61.0
27.3
5.0
6.9
43.6
1.0
1.1
0.1
2
Ni-Cu/P25-60ºC
Ni-Cu/P25-80ºC
Ni-Cu/P25-100ºC
Ni-Cu/P25-120ºC
62.0
76.3
89.2
98.0
14.3
13.6
12.5
11.0
64.5
46.0
35.1
19.0
20
38.5
52.3
70
1.2
0.9
0.1
1.5
3
Ni-Ag/P25-60ºC
Ni-Ag/P25-80ºC
Ni-Ag/P25-100ºC
Ni-Ag/P25-120ºC
64.0
76.0
90.5
98.0
14.5
12.7
10.9
9.0
60.9
44.4
35.9
18.0
17.5
40.2
42.5
76.0
7.1
3.7
0.7
1.0
4
Ni-Au/P25-60ºC
Ni-Au/P25-80ºC
Ni-Au/P25-100ºC
Ni-Au/P25-120ºC
60.0
77.0
92.65
98.0
14.1
13.1
12.7
11.0
70.86
47.37
27.3
12.2
13.1
36.3
49.6
79.0
1.94
3.23
0.4
0.8
Calibration of GC
Mixture of reactant and products
HCOL
HCAL
Reactant
COL
15
Concept of Lewis sites
C=O bond activation by electropositive Fe on Pt surface
Ref: Richard, J. Ockelford, A. Giroir-Fendler, and P. Gallezot, Catal.Lett., 3,53 (1989).
Summary
Conculsion
o Ni-Au/P25,Ni-Cu/P25 & Ni-Ag/P25 bimetallic systems are showing more activity
and selectivity, but when compared to monometallic Ni/P25.
o The strong interaction between Ni and Cu or Ag or Au was demonstrated to the
main reason for the enhanced catalytic activity of catalysts.
o The Electronic structure of the surface Ni atoms was modified upon the addition
of Cu or Ag or Au ,so reducibility of nickel increased.
o Improved the activity can be also ascribed to the high dispersion of Cu or Ag or
Au on nickel nanoparticles of the bimetallic catalysts.
HYDRGENOLYSIS OF BIO-MASS
DERIVED POLYOLS TO VALUE ADDED
CHEMICALS
R.Vijaya Shanthi,S.Sivasanker
National Centre for Catalysis Research,
I I T – M, Chennai.
Introduction
One of the most attractive routes of biomass utilization is its
direct conversion to valuable organic compounds which gets more
and more attention an ever .
An effective process for the biomass utilization is hydrogenolysis
of polyalcohols derived from biomass.
Hydrogenolysis has a great potential in the conversion of biomassderived polyols, such as sugars or sugar alcohols.
Present work
We had earlier reported studies on Ni, Pt and Ru supported on the basic
support, NaY for sorbitol hydrogenolysis. (Topics in Catalysis (2012) 55:897–
907.)
As a part of our investigations on the influence of the support on the
performance of supported metal catalysts we have now carried out
hydrogenolysis of glucose & glycerol over unconventional support, viz.
Hydroxyapatite
Materials based on Ca10(PO4)6(OH)2 (hydroxyapatite, HAP) have attracted
tremendous interest because of high stability at high temperatures and least
soluble in aqueous medium which will be very useful for reactions involving
aqueous medium .
Taking into account environmental and economical considerations, the
handling of hydroxyapatite used as a catalyst presents many advantages such as
to easier separation,recovery from the reaction mixture and thus, enhanced
recycling possibilities, which are now well established in fine organic synthesis.
HAP has recently received much attention in view of its potential usefulness as
adsorbent and most importantly as catalyst in solid/gas reactions.
The various products obtainable by hydrogenolysis of glucose
Crystalline structure of hydroxyapatite
Synthesis of HAP & preparation of catalysts
7.927g of (NH4)2HPO4 in 250ml solution( at a pH>12
(60–70 ml NH4OH) )+ 23.63 g of Ca(NO3)2 .4H2O
in 150ml solution
stirred at room temperature
refluxed for 4 h
Filtered, dried for 12 h at 120 °C
Calcined in air at 600 °C for 4 h
Support
HAP
Impregnation method(Ni -6 wt.%;Pt-1 wt.%;Ru-1 wt.%)
dried for 12 h at 120 °C
Calcined in air at 600 °C for 4 h
Reduced in H2 for 4 h at 400 °C (prior to use)
6%Ni/HAP;1%Pt/HAP;1%Ru/HAP
Catalyst
Characterization of HAP & the catalysts
XRD patterns
TEM images -
Catalyst
SBET
(m2/g)
Pvtot
(cm3/g)
Av.
pore
dia.(Å)
Metal dispersion
(%) [crystallite size,
nm]
HAP (Ca:P-1.58)
45
0.42
374
Ru(1%)-HAP
-
-
-
26 [2.2]
Pt(1%)-HAP
-
-
-
15 [11.4]
Ni(6%)-HAP
-
-
-
2.5 10.4]
Physicochemical property
The crystals are rod-like in shape & the particles are of
approximately 20–40 nm in diameter with 40–60 nm in length.
100
90
CONV.
Conversion
1,2-PD
EG
90
Conversion/selectivity (Wt%)
80
70
60
Wt (%)
100
SEL. (PD+EG)
50
40
30
20
80
70
60
50
40
30
20
10
10
0
0
P
P
AP
AP
AP
AP
HA
HA
t- H
u- H
u- H
u- H
NiNiP
C
R
C
%
%
%
%
%
6
1
6
1
12
12%
Effect of catalysts
180
190
200
210
220
Temperature C
Effect of temperature – 12%Ni/HAP
Conditions: 15% glycerol in water; press.: 60 bar; time: 6 h; stirring speed: 300rpm; G= glycerol;
PD = 1,2-propanediol & EG = ethylene glycol; A-absence of base; B-presence of base
Effect of solvent– 12%Ni/HAP
100
CONV.
SEL. (PD+EG)
90
90
80
80
80
70
70
70
60
60
60
50
50
50
40
40
40
30
30
30
20
20
20
10
10
10
0
0
Wt (%)
Wt (%)
90
100 100
A
0
O
H2
O+
H2
)
:50
(50
A
P
I
IPA
B
CONV.
O
H2
O
H2
SEL. (PD+EG)
)
:50
(50
A
P
+I
IPA
Recyclability – 12%Ni/HAP
100
A
CONV.
100
SEL. (PD+EG)
90
80
Conversion/selectivity (Wt%)
Conversion/selectivity (Wt%)
90
70
60
50
40
30
20
10
B
CONV.
SEL. (PD+EG)
80
70
60
50
40
30
20
10
0
Fresh
I Cycle
II Cycle
III Cycle
0
Fresh
I Cycle
II Cycle
III Cycle
A
The presence of base enhances the conversion & selectivity
Catalyst
Glucose
Conv.
(%)
Product Selectivity (wt%)
Dihydric
G
Others
alcohols
1,2 PD
EG
S
Ru/Hap
80
26
20
18
16
Ru/Hap+ Ca(OH)2
86
22
22
20
14
Pt(1%)-HAP
74
34
18
20
12
Pt/Hap+ Ca(OH)2
80
31
21
20
14
Ni/Hap
96
18
18
24
26
Ni/Hap+ Ca(OH)2
98
10
16
26
28
Conditions: 15% glucose in water; cat.: 0.2 g; temp.: 140 °C; press.: 60 bar; time: 6 h; stirring
speed: 1000 rpm; S = Sorbitol; G= glycerol; PD = 1,2-propanediol & EG = ethylene glycol;
trihydric(except glycerol) and higher alcohols; monohydric alcohols and :others
(methanol,ethanol&butanol); Ca(OH)2 , 0.25g.
Order of activity:
(A) Ni/Hap > Ru/Hap > Pt/Hap (in absence of Ca(OH2).
(B) Ni/Hap > Ru/Hap > Pt/Hap (in presence of Ca(OH2).
Effect of reaction parameters – 6%Ni/HAP
Temperature
SEL. (PD+EG)
Yield (PD+EG)
90
100
90
90
80
80
70
70
60
60
60
50
40
40
30
30
20
20
10
10
10
0
0
P
HA
Ni6%
P
HA
Pt1%
100
AP
-H
Ru
%
1
Conversion
Glycerol
1,2-PD
EG
70
50
0
90
80
50
Conversion/selectivity (Wt%)
Wt (%)
100
40
30
20
Conversion
Glycerol
1,2-PD
EG
HA
80
70
60
50
40
30
20
10
120
130
140
150
0
0.05
160
0.10
0.15
B
90
Conversion
Glycerol
1,2-PD
EG
80
70
60
50
40
30
20
0.20
0.25
0.30
0.35
0.40
Catalyst amount (g)
Temperature C
100
A
90
Catalyst amount
100
Conversion/selectivity (Wt%)
CONV.
Conversion/selectivity (Wt%)
100
Conversion/selectivity (Wt%)
Effect of catalysts
Conversion
Glycerol
1,2-PD
EG
80
70
60
50
40
30
20
10
10
0
0
0
1
2
3
4
5
6
7
8
9
10
11
12
13
Time (h)
0
1
2
3
4
5
6
7
9
10
11
12
Time (h)
Effect of run duration – 6%Ni/HAP
Optimum conditions
8
 Temp - 140 °C;
 Catalyst - 0.2g
 Run duration – 6 h
0.45
Recyclability – 6%Ni/HAP
100
Conversion
Glycerol
1,2-PD+EG
100
90
1,2-PD+EG
B
80
Conversion/selectivity (Wt%)
Conversion/selectivity (Wt%)
Glycerol
90
A
80
Conversion
70
60
50
40
30
70
60
50
40
30
20
20
10
10
0
0
Fresh
I Cycle
II Cycle
III Cycle
Fresh
I Cycle
II Cycle
III Cycle
(A) in the absence of Ca (OH)2and (B) in the presence of Ca(OH)2
Conditions: Temp., 140 °C; pressure, 60 bars; run duration, 6 h; catalyst,
0.2g; sorbitol, 15 g; water, 85 g; Ca(OH)2 , 0.25g.
The presence of base enhances the conversion & selectivity
marginally
Conclusion
The influence of the support on Hydrogenolysis of glycerol &
glucose was investigated over HAP metal supported catalysts.
The loading of the metals was: Ni, 6%; Cu, 6 %; Ru 1 %; and
Pt, 1 %. Ni/HAP & Ni/Hap were found to be the most active
and selective (for glycols) amongst all the catalysts.
The influences of temperature, catalyst loading and reusability
on sorbitol conversion and selectivity were investigated with
6%Ni/HAP catalyst. The influence of the addition of the base
Ca(OH)2 on conversion and product yields is also influenced
the conversion and selectivity of both glycerol & glucose.
A general observation is that the reaction proceeds better
in a basic medium, typically, in the presence of Ca(OH)2.
Mechanism of the hydrogenolysis of sorbitol
in the presence of a base
Photocatalytic reduction of Carbon dioxide
over Strontium titanate surfaces
V. Jeyalakshmi, K. R. Krishnamurthy & B. Viswanathan
NCCR, IIT Madras
Utilization of CO2 - A global endeavor
Global demand for energy to set to increase by 50 % by 2030
Fossil fuels continue to be the major source of energy
Utilization of CO2 - A global endeavor
Increase in CO2 emission levels- a matter of concern
Increase in earth’s average surface temp. - 0.6K in the last century
Green house effect, changes in weather patterns
CO2 management - A challenging task
Processes for CO2 conversion
 Chemical
.
 Photo-chemical
 Bio-chemical
 Photo bio-chemical
 Radio-chemical
 Electro-chemical
 Photo electro-chemical
 Photo bio-electrochemical
(MA Scibioh & B.Viswanathan
Proc.Ind.Natl. Sci.Acad.70A,407,2004)
Photo catalytic reduction that
utilizes solar energy which has
tremendous potential
Photo catalytic reduction of CO2 with H2O
Process & catalyst
Splitting of water to yield hydrogen
Reductive conversion of CO2 to hydrocarbons
Both steps proceeding via photo catalysis.
Bi-functional catalyst design to include components that are
active for both functionalities
suitable for activation with the most abundant visible light
Challenges for practical application
Maximization of hydrocarbons formation
Selectivity towards narrow range hydrocarbons
Choice of catalysts- Guiding principles
VB & CB potentials for selected semi-conductors relative to the
energy levels for CO2 redox couples in water
(T.Inoue, A.Fujishima,S.Konishi & K.Honda, Nature,277,637,1979)
Valence band top energy level to be suitable for splitting of water
Conduction band bottom energy level to be more negative with
respect to reduction potential of CO2
38
SrTiO3, Sr3Ti2O7 & Sr4Ti3O10
 SrTiO3, as one of the most promising photocatalysts, is now used in various
practical applications.
 In these materials , slabs of SrTiO3 are cut parallel to
the idealised cubic perovskite (100) planes and stacked
together , each slab being slightly displaced from the process.
Kudo et al. Chem. Soc. Rev., 38(2009) 253
CO2 Photo reduction on Strontium titanate surface
The large band gap sizes of early transition-metal oxides (>3.0eV) restrict
their photocatalytic activities to ultraviolet wavelengths.
Modified Strontium titanate catalysts
 Non metal doping (N doping)
 Metal doping (Fe doping)
(a) the charge carrier recombination time is largely influenced by the
presence of iron cations, (b) presence of iron induces a bathochromic effect, and (c) iron doped photocatalyst is efficient in several
important photocatalytic reduction and oxidation reaction
STO:N, Fe. Will exhibit high photocatalytic activities under vis
illumination, which is due to the decrease in the oxygen vacancies
because co doping maintains the charge balance.
Synthesis of SrTiO3
Polymerized complex method gives fine and well-crystalline powders with
a high surface area at relatively low calcination temperature and short
calcination time compared with a conventional solid state method.
Kudo et al. Chem. Soc. Rev., 38(2009) 253–278
Preparation of Strontium titanate
Ethylene glycol : Methanol(1:2).
2 mole of C16H36O4Ti was added.
0.5mole of Citric acid + 3mole of Sr(NO3)2 + 2mole of
Urea/Thiourea or 3% Fe2O3 added to the mixture .
The solution was stirred at
130°C for 20 hrs.
The resulting polymerized complex
gel was pyrolyzed at 350 °C
Precursor was calcined at 900°C for 2 h.
N,S/Sr3Ti2O7 or Fe2O3/Sr3Ti2O7
Methanol, Ethylene glycol , citric acid should be in the molar ratio of 1:2:0.5.
H.Jeong et al. International Journal of Hydrogen Energy 31 (2006)1142 – 1146
XRD pattern for SrTiO3
The shift indicates that a part of Iron at least is homogeneously doped into the
SrTiO3 lattice. Ionic radii of six-coordinated Fe3+ (0.62A˚) are almost the same
as Ti4+ ion (0.61A˚).
XRD pattern for Sr3Ti2O7
The shift indicates that a part of Iron at least is homogeneously doped into the
Sr3Ti2O7 lattice. Ionic radii of six-coordinated Fe3+ (0.62A˚) are almost the same
as Ti4+ ion (0.61A˚).
XRD pattern for Sr4Ti3O10
The shift indicates that a part of Iron at least is homogeneously doped into the
Sr4Ti3O10 lattice. Ionic radii of six-coordinated Fe3+ (0.62A˚) are almost the
same as Ti4+ ion (0.61A˚).
DR spectra for the catalysts
Catalyst
Crystalline
size (nm)
Band gap
(nm)
SrTiO3
28.9
3.05
Fe/NS/SrTiO3
33
3
Sr3Ti2O7
46
3.14
Fe/NS/Sr3Ti2O7
39
2.4
Sr4Ti3O10
52.7
3.12
Fe/NS/Sr4Ti3O10
46.7
2.9
Photo luminescence spectra
of the catalysts
Co doping increases exciton life time.
SEM Image
SrTiO3
Fe NS SrTiO3
Sr3Ti2O7
Sr4Ti3O10
Fe NS Sr3Ti2O7
Fe NS Sr4Ti3O10
Reaction & Analysis
Reactor volume - 650 ml
Reaction medium - 400 ml of 0.2 N aqueous NaOH.
Temperature- 298K
Catalyst loaded - 0.4g. Dispersed in the medium with continuous
agitation-400 rpm
CO2 was bubbled for 30 min.
pH of the medium- Reduced to 8.0 after saturation with CO2 from
the initial value 13.0
Reaction medium was irradiated through a 5cm dia. quartz window.
Light source-High pressure Hg lamp-UV-Vis radiation -300-700 nm
77W power
The products were analyzed using Perkin Elmer Clarus 500 Gas
chromatograph - Poroplot Q, 30 m, at 150ºC with FID for analysis of
hydrocarbons and Mol.Sieve 5A column for H2 & O2 analysis
Gas (0.2 ml) and liquid (1 µl) phase samples were withdrawn every
two hours from the reactor and injected into the GC.
•
•
Reactor volume
Catalyst loaded
- 650 ml, Reaction medium - 400 ml of 0.2 N NaOH .
- 0.4g . CO2 was bubbled for 30 min.
•
•
Reactor volume
Catalyst loaded
- 650 ml, Reaction medium - 400 ml of 0.2 N NaOH .
- 0.4g . CO2 was bubbled for 30 min.
•
•
Reactor volume
Catalyst loaded
- 650 ml, Reaction medium - 400 ml of 0.2 N NaOH .
- 0.4g . CO2 was bubbled for 30 min.
•
•
Reactor volume
Catalyst loaded
- 650 ml, Reaction medium - 400 ml of 0.2 N NaOH .
- 0.4g . CO2 was bubbled for 30 min.
•
•
Reactor volume
Catalyst loaded
- 650 ml, Reaction medium - 400 ml of 0.2 N NaOH .
- 0.4g . CO2 was bubbled for 30 min.
•
•
Reactor volume
Catalyst loaded
- 650 ml, Reaction medium - 400 ml of 0.2 N NaOH .
- 0.4g . CO2 was bubbled for 30 min.
Photo reduction of CO2- Cumulative
conversion
Catalyst
Products formed after 20hrs of irradiation (μmol/g)
Conversi
on (%)
CH4
C2H4
C2H6
CH3OH
C2H4
O
C2H5
OH
C3H6
O
C3H6
Total CO2
consumed
SrTiO3
0.42
0.3
0.14
212
0
89.2
0
0
391.8
0.55
Fe/NS/SrTiO3
0.5
0.6
0
498.9
0
66.4
0
0.2
567.8
0.79
Sr3Ti2O7
0.5
0.2
0.2
248.8
7.6
53.4
0
0.2
373
0.5
Fe/N,S/Sr3Ti2O7
0.1
5.4
0.2
561
1.6
284
25
0.9
1221.7
1.7
Sr4Ti3O10
0.22
0.8
0.2
222.3
0
129.
0
0.8
485.4
0.68
Fe/NS/Sr4Ti3O10
0.28
0
0.2
409.6
1.8
123.6
0
0
661.1
0.93
Activity pattern for CO2 photo reduction
Summary
 SrTiO3, Sr3Ti2O7 ,Sr4Ti3O10 & modified samples were prepared by
polymerised complex method.
 Layered strutured shows impured photocatalytic activity compared to
neat perovskite SrTiO3, which is probably due to separation of active site
and increased the exciton life time.
 SrTiO3 codoped with nitrogen and Iron exhibited the high photocatalytic
activity due to the decrease of the oxygen vacancies, which may act as
electron-hole pair recombination centers, because codoping with Fe3+ and
N3- ions maintained the charge balance.
Thank you!
pH dependent carbonate ions in solution
After bubbling carbon dioxide the most likely species present in the reaction
medium is HCO3-
Role of alkaline (NaOH) reaction
medium
OH- ions act as hole scavengers, form OH radicals, and
reduce the electron-hole recombination rate. Increase in
lifetime of photo electrons would facilitate the reduction
of CO2.(I-H Tseng et al.,Appl.Catal.B Env.37,37,2002)
Alkaline medium increases the solubility of CO2.
Criteria for selection of SC photo-catalysts
1.
2.
3.
4.
The SC should have narrow band gap to absorb as much light as possible.
The bottom of the conduction band must be more negative than the
reduction potential of water to produce hydrogen and the top of the valence
band must be more positive than the oxidation potential of water to evolve
oxygen.
Efficient charge separation and fast charge transport simultaneously avoiding
the bulk and surface recombination are essential to migrate the photogenerated charge carriers to the surface reaction sites.
Kinetically feasible surface chemical reactions must take place between the
charge carriers and water or other molecules and the backward chemical
reaction should be capable being suppressed.
Outcome Develop SC specific bulk and surface propeties and energy band
structures to satisfy these demands
Xinchen Wang, Kazuhiko Maeda, Arne Thomas,
Kazuhiro Takanabe, Gang Xin, Johan M.
Carlsson, Kazunari Domen & Markus Antoniett :
A metal-free polymeric photocatalyst for
hydrogen production from water under
visible light, Nature Materials 8, 76 - 80 (2009)
a, Schematic diagram of a perfect graphitic carbon nitride sheet constructed from
melem units. b, Experimental XRD pattern of the polymeric carbon nitride, revealing a
graphitic structure with an inter planar stacking distance of aromatic units of
0.326 nm. c, Ultraviolet–visible diffuse reflectance spectrum of the polymeric carbon
nitride. Inset: Photograph of the photo-catalyst.
a, Density-functional-theory band structure for polymeric melon calculated along the
chain (Gamma–X direction) and perpendicular to the chain (Y–Gamma direction). The
position of the reduction level for H+ to H2 is indicated by the dashed blue line and the
oxidation potential of H2O to O2 is indicated by the red dashed line just above the
valence band. b, The Kohn–Sham orbitals for the valence band of polymeric melon. c,
The corresponding conduction band. The carbon atoms are grey, nitrogen atoms are
blue and the hydrogen atoms are white. The isodensity surfaces are drawn for a charge
density of 0.01qe Å-3.
A typical time course of H2 production from water containing 10 vol% triethanolamine
as an electron donor under visible light (of wavelength longer than 420 nm) by
(i) unmodified g-C3N4 and (ii) 3.0 wt% Pt-deposited g-C3N4 photocatalyst. The reaction
was continued for 72 h, with evacuation every 24 h (dashed line). Unmodified gC3N4 also photocatalysed steady H2 production from aqueous methanol solution (10
vol %)
Steady rate of H2 production from water containing 10 vol% methanol as an electron
donor by 0.5 wt% Pt-deposited g-C3N4 photo-catalyst as a function of wavelength of
the incident light. Ultraviolet–visible absorption spectrum of the g-C3N4 catalyst is also
shown for comparison.
Time courses of O2 production from water containing 0.01 M silver nitrate as an
electron acceptor under visible light (of wavelength longer than 420 nm) by 3.0 wt%
RuO2-loaded g-C3N4. La2O3 (0.2 g) was used as a buffer (pH 8–9).
Thermal stability 873 K chemical stability acid base and organic solvents, Eg ~ 2.7 eV
band positions suitable for water reduction and oxidation. Shining star of photocatalysis
Synthesis of C3N4
Thermal condensation of nitrogen
rich precursors such as cyanamide,
dicyandiamide, melamine
Texture modification, elemental
doping, copolymerization
Viswanathan B
To:
Perspectives and outlook
1.
2.
3.
4.
5.
6.
7.
8.
9.
Amenable for modification
Medium band gap with HOMO and LUMO positions for electron
transfer with powerful chemical potential
Artificial photosynthesis, oxygenation, reduction, base catalysis,
aromatic, double and triple bond activation.
Metal free, thermal, chemical stability, tunable electronic structure,
abundant, cheap
Rates are still low role of covalence in reversible bonds formed or split
Enzyme like functionality possible
Structure and catalytic activity correlation?
Increasing the domain size and improvement of electrochemical
properties due to incomplete poly condensation
Only a few reactions have been addressed - substrate specific
reactions will be the future challenge
3
4
5
7
8
6
NCCR
27th July 2014
THE VISION
Emerge as the Premier National Centre for Catalysis
focusing on:
Building Human Resource and Knowledge Capital.
Establishing Advanced R & D Facilities.
Initiating Research Programs in Frontier Areas.
Cultivating Vibrant Partnership Among the Trinity of
Academy-Research-Industry.
T H E MAN DAT E
Actively build human capacities and expertise manpower in the area of
Catalysis through structured educational programs at various levels
Undertake advanced research in frontier areas of basic sciences
relating to Catalysis:
◙ New materials
◙ Surface Science
◙ Energy Conversion Processes
◙ Theoretical Science
Solicit support from industries for applied research in cutting-edge
technology areas
Emerge as a knowledge center & store house of relevant information
to user industries towards reliable problem solving, testing & training
Initiate collaborative research programs with universities, national and
international institutes and laboratories
NCCR
NCCR
Clear focus
Surface science
New materials
Energy conversion processes
Theoretical approaches
Research programmes in frontier areas
Ordered meso porous materials
Reduction of carbon dioxide in combination with
water splitting to yield fuels and chemicals
Splitting of water for hydrogen generation
Fixing of nitrogen as ammonia.
Alternate routes for hydrogen generation
New materials for hydrogen storage
Design and fabrication of alternate noble metal
based electrodes for fuel cell -Synthesis of new
materials
Biomass conversion to platform chemicals
Surface analysis at atomic and molecular level
by electron spectroscopy
Theoretical studies for catalyst development –
employing DFT and other modern theories for
condensed matter applications.
NCCR has successfully achieved
the goal/ mandates
Research Scholars Orientation programs-14
M Tech Degree Course in Catalysis Technology-4
Ph. D Degree Course- 5/25
Advanced research facilities in Catalysis
Research programmes in frontier areas
Collaborations with International and National
Universities/Institutes
 Establishing vibrant academia-industry
partnership- 12 industry sponsored research
projects
 Charting out a road map for future






NCCR-Research Contributions
Publications in journals
228
Presentations in Seminars/Symposia
248
Patents
18
Books/Chapters
29
Catalysis
Nearly two centuries old; continues to be an ever-green
branch of science, exciting & vibrant
Tremendous impact on society & science
Four Nobel prizes in Catalysis in the last decadeAsymmetric catalysis, Olefins Metathesis
Surface chemistry, Pd catalyzed Cross-couplings
> 30 journals explicitly devoted to Catalysis besides
ACS & RSC journals
New journals started in 2011-ACS- Catalysis ; RSCCatalysis –Science & Technology
Undergoing a renaissance-science & technology
Shift in focus- from chemical processes to Energy &
Environment- major concerns of modern society
Set to emerge as a source for sustainable solutions
Design of Catalysts
The approach ……..
Basic functionalities to be built in : Activity, Selectivity,
Life, Regenerability, Thermal & Mechanical stability
Selection of catalytic components that generate the
functionalities for a specific process- Empirical → Rational
Architectural approach in effective integration of the
components.
Scientific basis for selection & integration-theoretical &
experimental validation - Significant progress
Concept of active centre
The basis for catalyst design
Active sites on the surface
Supported metal catalysts-guiding principles
Pt metal-Bulk Crystal-Crystal planes- Surface structure--active sites
Bonding/Reactivity of reactants on terrace/step/kink sites is
determined by the co-ordination numbers/co-ordinative
unsaturation
For cyclic hydrocarbon reactant
C-H bond activation – step sites- Dehydrogenated product
C-C- bond activation - kink sites- Ring opening
Active phase composition-Structure-Size-Shape
Surface structure-Selectivity
Topics in Catalysis (2010) 53:832–847
Enabling techniques & tools
The resurgence
Advent of nano science & technology
Role of size and shape of nano particles
Size-Activity ; Shape –Selectivity
Range of catalyst preparation techniques
Colloidal synthesis, self-assembly, use of dendrimers
Synthesis & characterization of New materials
Ordered mesoporous materials, MOF, CNT, Graphenes
Advanced theoretical-computational methods
Surface sensitive analytical techniques-molecular/atomic level
Combinatorial catalysis
High throughput catalyst evaluation & preparation
Rational approach to design of catalysts
Novel catalyst architectures
Design of active centres
Process
Mechanistic pathways
Energetics of
Reactant-surface
interactions
Theoretical studies
Surface structure
Preparation methods
Well defined morphology
Size & Shape control
Exposure of specific planes
Analytical techniques
Surface reactivity
Performance
Adsorption
Activation
Surface reactions
Desorption
Activity
Selectivity
Stability
Modern approaches
Sustainable processes and products
through Catalysis- Challenges
Energy-Environment-Renewable feed-stocksDesign, Synthesis and Application of New materials
NCCR- Future activities
Emphasis on
•
Educational activities
•
Training and manpower
development
•
New areas of research-basic &
applied
•
Strengthen research facilities
•
Expand research collaborations
NCCR-Plan for Next 5 Years
Road ahead
To spread its wings over several emerging and new frontiers in the science
of catalysis.
To carve out its own place within IIT Madras as a vibrant entity with
significant contributions in contemporary topics in Catalysis.
Focus for the next five years
Intensifying Academic Research leading to publications in high impact
journals.
Aggressively pursuing Industry supported or industry oriented projects
that would lead to Patent Disclosures covering cutting-edge product
development/process technologies.
Strengthening Academic activities related to:
• Research for imparting knowledge and training to young researchers.
• Resource generation in terms books, e-books and databases.
Expanding and strengthening international collaboration with other
Catalysis Research Centres across the globe and provide a platform for
Indian Scientists a uniform play ground to compete internationally.
To tread along the growth path & strive for recognition at global level
NCCR on Global Horizon
Catalysis has emerged as a leading branch of science in the last two
decades and expected to grow further
Amply reflected with the initiation of specialized journals by RSC, ACS
Catalysis will continue to flourish and blossom into a branch of science
attracting fundamental knowledge creation and helping to achieve
sustainable living in this universe.
Energy-Environment- Life style & Economy
The economic and environmental benefits of Catalysis have been
established beyond doubt and will continue to be the centre stage of
knowledge generation in the decades to come.
India has in the past evolved path-breaking methodologies for a
sustainable society in this world, could take lead and become one of
the torch bearers in modern science.
NCCR would play a major role in the realization of India’s potential in
this branch of science and emerges as the knowledge centre.
NCCR on a Growth Path
NCCR has the potential to emerge as a:
• Knowledge storehouse not only for this country but to the
entire world
• International centre for creation of skilled and competent
human resources
• Centre where not only research in cutting edge technologies
will be developed but also a nucleus for generating newer
directions for research and practice in industry.
Above all, a Centre of excellence in an academic and applied area
like Catalysis will be directly reflecting in the economy of the
country.
The Centre will have a leading role and contribute towards the
advancement of science & technology in the years to come
On this day, 27th July 2014, let us all
re-dedicate ourselves to the task of
building a strong and vibrant NCCR
Thank you !