复合氧化物在催化脱硝领域中的研究及应用
Research & Application of Mixed Oxides for Selective
Catalytic Reduction of NOx
by
Chen Zhi-hang
Ph.D.
Atmospheric Environment & Pollution Prevention Research Center
South China Institute of Environmental Science, MEP
Contents
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 Introduction
 Mixed-oxide
Catalysts for Industrial Boiler
at High Temperature
 Mixed-oxide
Catalysts for SCR at Low
Temperature
 Mixed-oxide
Catalysts for Glass Kilns at
Middle-low Temperature
 Conclusions
& Prospect
Introduction
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49%
Beijing
5%
NOx emission
Transportation
Power Plant
Others
46%
Frequency Area%
Nitrogen oxide emissions from
Shanghai
power plants, industrial boilers, and
kilns accounted for 70% in China.
(Journal
of Environmental Sciences, 2008, 28(12):
2470-2479)
Guangzhou
<5%
5~10%
10~25%
25~50%
50~75%
>75%
No data
Acid Rain Distribution in China
67.4%
6.8%
10.4%
8.2%
5.4%
1.8%
Technology for DeNOx
Adsorption
Method
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SNCR
NH3-SCR
 Commercialized
 High efficient
NH3
Plasma
Method
SCR
DeNOx
SCR Reaction:
4 NO  4 NH 3  O2  4 N 2  6 H 2O
Microbial
Process
G 298  1627kJ / mol
Electrolytic
Process
SCR——selective catalytic reduction
SNCR——selective Non catalytic reduction
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Mixed-oxide Catalysts for Industrial
Boiler at High Temperature
SCR for flue gas denitrification in power
plant boilers
Honeycomb Corrugated plate
SCR DeNOx Reactor in power
plant boilers.
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Flat
SCR
V2O5-WO3(MoO3)/TiO2
The process flow diagram of SCR
denitrification in power plant boilers.
Flue gas denitrification pilot test
——Small and medium-sized boiler
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The honeycomb SCR
catalyst developed by
Tsinghua University
et. al.
Test device for flue gas
denitrification(200 Nm3/h)
 National High Technology Research and Development Program of China (2006）
 Guangdong-Hongkong Project of The Major Breakthroughs in Key Areas
（2008）
Demonstration projects of SCR
——Industrial boiler
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SCR DeNOx Reactor
Demonstration projects of
SCR denitrification
(35 t/h chain-grate boiler in
Pacific(Panyu) Textiles Limited,
flow rate: 70000 Nm3/h )
SCR Denitrification tower of Pacific co.
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Mixed-oxide Catalysts for SCR at Low
Temperature
SCR at Low Temperature
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SCR
SCR
at 80~150℃
Energytemperature
efficient andfor
cost
saving

Suitable
catalysis(SCR
at 350~450℃)
Typical
hasAs
low
activity under low temperature

Dust
(e.g., SCR
K2O,catalyst
CaO, and
2O3) and SO2 deactivate the catalyst
 Novel Catalyst should be developed for low temperature
Catalysts Developed for Low-Temperature
SCR[1~12]
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
MnOx、MnOx/TiO2、CuOx-MnOx and MnOx-CeO2 etc..

Mn-Cu/TiO2、Mn-Cr/TiO2 catalysts showed good activity (CNO:
60％, 120oC, NO/NH3 =1 at 0.2%, GHSV=8,000 h-1)

MnOx-CeO2 exhibited well activity(100oC, CNO:~90%, NO/NH3
=1 at 0.2%，GHSV=42,000 h-1)

Sulfur dioxide and vapour resistant are weak.

Mixed-oxide catalyst may be a kind of prospective lowtemperature SCR candidates
[1] Catal. Commun. 8 (2007) 2096.
[2] Appl. Catal. A 327 (2007) 261.
[3] Catal. Commun. 8 (2007) 329.
[4] Appl. Catal. B 79 (2008) 347.
[5] Catal. Commun. 8 (2007) 1896.
[6] Angew. Chem. Int. Ed. 40 (2001) 2479.
[7] Appl. Catal. B 44 (2003) 217.
[8] Catal. Today 111 (2006) 236.
[9] Appl. Catal. B 51 (2004) 93.
[10] Appl. Catal. B 62 (2006) 265.
[11] Chem. Commun. 7 (2003) 848.
[12] Ind. & Eng. Chem. Res. 45 (2006) 6444
Screen of Low-temperature SCR Catalysts
100
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100
Ni(0.5)-CoOx(SR)(600)
Zr(0.5)-CrOx(SR)(600)
80
Co(0.5)-CrOx(SR)(600)
60
NOx conversion (%)
NOx conversion (%)
80
Fe(0.5)-CoOx(SR)(600)
40
20
0
100
125
150
175
o
Temperature ( C)
200
60
Sr(0.5)-MnOx(SR)(600)
40
Co(0.5)-MnOx(SR)(600)
Ni(0.5)-MnOx(SR)(600)
20
0
100
Cr(0.5)-MnOx(SR)(600)
Fe(0.5)-MnOx(SR)(600)
125
150
175
200
o
Temperature ( C)
Activity of mixed oxides prepared by SR method
Activity evaluation conditions:[NO]=[NH3]=1000 ppm[,O2]=3%,[SO2]=100 ppm,GHSV=30,000 h-1
 Cr-MnOx、Fe-MnOx are potential catalysts
Cr-MnOx SCR activity at Low temperature
100
New crystal
▼
60
40
CrOx
▼
▼
▼
▼ ▼
◇
◇
◇
▲
◇
◇
▲
◇▲
▲▲
▲▲ ▲
◇
▽
▽
▽
▽
▽▽
▽
▽ ▽ ▽ ▽ ▽▽
▽
MnOx
20
▲Cr2O3 ◇Mn2O3
d
▼
◇
Intensity (a.u.)
NOx conversion (%)
80
▼CrMn1.5O4 ▽Mn3O4
▼
▼
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▲
▲
▲
CrOx-MnOx
Cr(0.5)-MnOx
c
b
▽
▽
▲
▲
▲ ▲
▲
40
50
▲
a
▲
▲
▲ ▲▲ ▲▲
0
80
100
120
140
160
180
o
Temperature ( C)
200
220
10
20
30
60
o
2( )
SCR activity and XRD patterns of (a) CrOx; (b) MnOx; (c)
CrOx-MnOx; (d) Cr(0.5)-MnOx catalysts
70
80
▼ CrMn1.5O4 ▽ Mn3O4 ◆ MnO
▼
Cr(0.5)-MnOx
▼
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▼
Cr(0.4)-MnOx
▼
▼
▼
▼
▼
Cr(0.3)-MnOx
◆
Cr(0.3)-MnOx
Cr(0.2)-MnOx
Cr(0.2)-MnOx
▽ ◆
◆
Cr(0.1)-MnOx ▽
▽
10
20
▽
▽
30
▽
40
▽
◆
▽▽
▽
▽ ▽▽
50
60
◆
Intensity (a.u.)
▼
Cr(0.4)-MnOx
◆
▽ ▽
70
80

2 
XRD patterns and SEM images of the Cr-MnOx
catalysts doped by different Cr content
Cr(0.1)-MnOx
Mechanism studying
——Cr-MnOx Structure analysis
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MnO
Cr2O3
CrMn1.5O4
Bond length of crystals
Crystal
Mn3O4
MnO
Cr2O3
CrMn1.5O4
Mn3O4
 Oxygen bridge between Cr and
Bond
Bond-length
Mn-O
2.2922Å
Mn in the form of Cr-O-Mn;
Mn-O
1.9475Å
Mn-O
2.0142Å
 Cr-O bond in CrMn1.5O4 is
Mn-O
2.2215Å
Cr-O
2.0367Å
Cr-O
1.9458Å
Mn-O
2.3509Å
Cr-O
1.4686Å
shorter than those of CrOx
Cell of CrMn1.5O4
 Mn-O bond in CrMn1.5O4 is
longer than those of MnOx
Mechanism studying
——Cr-MnOx Raman spectra measurement
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 Raman
Cr(0.5)-MnOx
shift of CrOx in lower
wave number without presenting
in mixed oxides conforms the
formation of new phase;
Cr(0.4)-MnOx
Cr(0.3)-MnOx
 New
Raman shift appears and
increases with the increasing of
Cr content;
Cr(0.2)-MnOx
Cr(0.1)-MnOx
Mn3O4[16-18]
Cr2O3[13-15]
MnOx
CrOx
200 300 400 500 600 700 800 900
-1
Raman shift (cm )
Raman spectra of catalysts
 Raman
shift at 539.3 and
642.7cm-1 are the characteristic
shifts of Cr-O-Mn in CrMn1.5O4
[13] J. Appl. Phys. 99 (2006) 053909;
[14] Mater. Sci. Eng. B 118 (2005) 74;
[15] J. Appl. Phys. 103 (2008) 023507;
[16] J. Electrochem. Soc. 140 (1993) 3065;
[17] J. Mater. Chem. 11 (2001) 1269;
[18] J. Catal. 150 (1994) 94
Mechanism studying
——Cr-MnOx XPS measurement
2+
Mn
2+
Cr Cr3+
(A)
Cr
c
4+
Cr 2p
-
b
2-
OH /CO3
c
Intensity (a.u.)
Intensity (a.u.)
(C)
5+
Mn
b
O 1s
2-
O
(B)
regenerated
c
Intensity (a.u.)
Mn 2p
3+
Mn
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used
b
a
fresh
a
a
640
645
650
655
Binding Energy (eV)
660
570
575
580
585
590
Binding Energy (eV)
595 525
530
535
540
Binding Energy (eV)
XPS spectra for (A) Mn 2p, (B) Cr 2p, and (C) O 1s of the Cr(0.4)-MnOx
catalysts: (a) fresh catalyst, (b) used catalyst, (c) regenerated catalyst.
Mechanism studying
——Cr-MnOx XPS measurement
Binding energies (eV) of core
electrons of Cr(0.4)-MnOx catalysts*
XPS
spectra
Cr 2p (eV)
Concn(%)
Mn 2p (eV)
Concn(%)
O 1s (eV)
Concn(%)
Element
valence
Used
Regenerat
ed
Cr2+
575.6(13.9)
575.7(16.8)
575.7(19.7)
Cr3+
576.7(42.2)
576.7(49.9)
576.6(38.0)
Cr5+
578.4(43.9)
578.3 (33.3)
578.5(42.3)
Mn2+
640.4(14.6)
640.5(15.5)
640.5(16.0)
Mn3+
641.9(54.2)
641.9(46.9)
642.2(60.6)
Mn4+
644.6(31.2)
644.5(37.6)
644.8(23.4)
O2-
529.8(71.0)
529.8(73.9)
529.9(72.2)
531.6(29.0
531.7(26.1)
531.8(27.8)
3
2-
* Surface concentration of different Mn, Cr and O states
are in parenthesis
Regenerated catalyst
Cr(0.4)-MnOx Catalysts
Fresh
OH/CO
After 500h SCR
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Cr5+
10.6%
Mn3+ 7.3%
Cr3+
7.7%
Mn4+ 6.4%
Cr5+
Normal
pressure &
temperature
plasma
treatment
9.0%
Mn3+ 13.7%
Cr3+
11.9%
Mn4+ 14.2%
Mechanism studying
——mechanism elucidation
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2 O-ads
O2
NO  Mn4  NOads   Mn3
2Mn3+
2Mn4+
Redox
CrMn1.5O4 Electronic transfer
Cr5+
Reaction
Cr3+
2 NO2
O2  Cr 3  Cr 5  2Oads 
NOads   Oads   NO2
Cr 5  2Mn3  Cr 3  2Mn4
2 NO
2 NO+ads
Redox catalytic cycles over
Cr(0.4)-MnOx catalysts
Journal of Catalysis, 2010, 276: 56-65.
Industrial & Engineering Chemistry Research, 2012, 51: 202-212.
Industrial & Engineering Chemistry Research, 2014, 53: 2647–2655.
Pilot test of Low-temperature SCR
The Low-temperature
SCR catalyst
developed by
Research Center for
Eco-environmental
Science, CAS et. al.
 National Natural Science Foundation of China（2008）
 National High Technology Research and Development Program
of China (2009）
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Test device for Lowtemperature SCR
(Circulating fluidized bed boiler in
Guangzhou Huiteng Textiles
Limited, flow rate: 5000 Nm3/h )
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Mixed-oxide Catalysts for Glass Kilns at
Middle-low Temperature
Middle-low temperature SCR for glass kilns SCIES
Middle-low temperature SCR
 Work at 180~300℃
 High activity
 Strong ability of sulfur tolerant
The flue gas emission from glass kiln of
China South Glass Group(Guangzhou)
(The concentration of SO2、NOx is very
high(about 500~3000mg/m3)
The temperature of flue gas is low(＜ 280℃)
The process flow diagram of SCR
for glass kiln.
Screen of Middle-low Temperature
SCR Catalysts
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100
90
NOx conversion (%)
80
70
2V8Co/TiO2(F)
60
2V8Fe/TiO2(F)
50
2V8Ni/TiO2(F)
40
2V8Cu/TiO2(F)
30
2V8Mn/TiO2(F)
20
3V7Mn/TiO2(F)
3V7Fe/TiO2(F)
10
3V7Cu/TiO2(F)
0
200
225
250
275
300
325
o
Temperature ( C)
SCR activity of VM/TiO2 catalysts
350
Effect of SO2
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100
90
NOx conversion (%)
80
70
2V8Co/TiO2(F)
60
2V8Fe/TiO2(F)
50
2V8Ni/TiO2(F)
40
2V8Cu/TiO2(F)
30
2V8Mn/TiO2(F)
20
3V7Mn/TiO2(F)
3V7Fe/TiO2(F)
10
3V7Cu/TiO2(F)
0
1h
2h
3h
4h
Time (h)
Effects of SO2 on NOx conversions over VM/TiO2 catalysts at 275oC.
Reaction conditions: [NO]=[NH3]=1000 ppm, [O2]=3%, [SO2]=600 ppm, GHSV=60,000 h-1
XPS measurement
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2V20Cu/TiO2
V4+
2V16Cu/TiO2
2V12Cu/TiO2
V5+
2V8Cu/TiO2
2V2Cu/TiO2
VCuMn/TiO2 & VCoMn/TiO2 Catalysts
SCIES
VCoMn/TiO2
VCuMn/TiO2
100
100
90
80
70
60
50
2V1Cu9Mn/TiO2(F)
40
2V2Cu8Mn/TiO2(F)
30
2V3Cu7Mn/TiO2(F)
20
2V5Cu5Mn/TiO2(F)
10
NOx conversion (%)
NOx conversion (%)
80
2V1Co9Mn/TiO2(F)
2V2Co8Mn/TiO2(F)
60
2V3Co7Mn/TiO2(F)
2V4Co6Mn/TiO2(F)
2V5Co5Mn/TiO2(F)
40
2V6Co4Mn/TiO2(F)
2V7Co3Mn/TiO2(F)
20
2V8Co2Mn/TiO2(F)
2V8Cu2Mn/TiO2(F)
0
200
225
250
275
300
o
Temperature ( C)
325
350
2V9Co1Mn/TiO2(F)
0
200
225
250
275
300
o
Temperature ( C)
SCR activity of VCuMn/TiO2 & VCoMn/TiO2 Catalysts
325
350
Effect of SO2
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VCoMn/TiO2
100
100
80
80
60
2V1Cu9Mn/TiO2(F)
40
2V2Cu8Mn/TiO2(F)
2V3Cu7Mn/TiO2(F)
20
2V5Cu5Mn/TiO2(F)
NOx conversion (%)
NOx conversion (%)
VCuMn/TiO2
2V1Co9Mn/TiO2(F)
2V2Co8Mn/TiO2(F)
60
2V3Co7Mn/TiO2(F)
2V4Co6Mn/TiO2(F)
2V5Co5Mn/TiO2(F)
40
2V6Co4Mn/TiO2(F)
2V7Co3Mn/TiO2(F)
20
2V8Co2Mn/TiO2(F)
2V8Cu2Mn/TiO2(F)
0
2V9Co1Mn/TiO2(F)
0
1
2
3
Time (h)
4
1
2
3
4
Time (h)
Effects of SO2 on NOx conversions over VCuMn/TiO2 & VCoMn/TiO2 catalysts at 250oC.
Reaction conditions: [NO]=[NH3]=1000 ppm, [O2]=3%, [SO2]=600 ppm, GHSV=60,000 h-1.
Advanced Materials Research, 2012, 550-553: 128-131.
Journal of Fuel Chemistry and Technology, 2012, 40(4):469-474.
Forming of Catalysts
The vacuum refining
mud machine
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Hydraulic extruder
 Natural Science Foundation of Guangdong (2011）
 National Natural Science Foundation of China
（2013）
Conclusion & Prospect
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
Localization of Commercial SCR catalyst has been
made progress. How to reduce the cost of catalyst,
establish of catalyst regeneration center.

Novel Cr-MnOx, Fe-MnOx, Mn-Zr catalysts with well
low-temperature SCR activity have been developed;
If we can not solve the problem of high activity at low
temperature( ＜ 120 ℃ ) ， should we change our
thinking.

Series of VMn, VCu, and modified catalysts are
studying systematically. How to improve the activity
of the catalyst under high concentration of SO2 is a
huge challenge.
Acknowlegment
Ministry of Environmental Protection, China
Ministry of Science Technology, China
National Natural Science Foundation of China
Natural Science Foundation of Guangdong, China
Department of science and technology of Guangdong Province
Department of science and information technology of Guangzhou
South China University of Technology
Thank you for your attention！