The NH3-SCR performance of fresh and
hydrothermal aged Fe-ZSM-5 in standard and
fast SCR reactions
Xiaoyan Shi, Fudong Liu, Lijuan Xie, Wenpo Shan, Hong He∗
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,
Beijing 100085, China
This Supporting Information includes:
1. The detail information about catalyst preparation.
2. Figures S1-S5 and Table S1
∗
Corresponding author e-mail: [email protected]
S1
Figure captions
Figure S1 Experimental UV-Vis spectra and deconvoluted sub-bands of fresh and
Aged Fe-ZSM-5.
Figure S2 Rate constant k for NO conversion at 190 oC-300oC in fast SCR reaction: (a)
NO2/NOx = 0.3 (b) NO2/NOx = 0.5
Figure S3 comparison of fast SCR over fresh and hydrothermal aged Fe-ZSM-5
catalysts in fast SCR with NO2/NOx=0.3. (a) NO, NO2 and NH3 NOx conversion, (b)
N2O production. Reaction condition: 150 ppm NO2, 350 ppm NO, 500 ppm NH3, 5
vol.% O2, N2 balance; 50 mg catalyst, total flow of 500 ml/min and GHSV of 320 000
h-1.
Figure S4 NH3 consumption and twice NO consumption in fast SCR over fresh and
aged Fe-ZSM-5. Reaction condition: 250 ppm NO, 250 ppm NO2, 500 ppm NH3, 5
vol.% O2, N2 balance; 50 mg catalyst, total flow of 500 ml/min and GHSV of 320 000
h-1.
Figure S5 H2-TPR profiles of fresh and aged Fe-ZSM-5. Conditions: 10%H2/Ar,
heating ramp 20 oC/min.
S2
1. Catalyst preparation
Fe-ZSM-5 catalyst was prepared by Solid state ion exchange method. 10 g H-ZSM-5
and a suitable amount of anhydrous FeCl3 were mixed in a ball mill for 1h. Then the
mixture was placed in a quartz tube reactor and heated to 600 oC with a temperature
ramp of 5 oC/min in flowing N2 (200 ml/min) and kept at this temperature for 2 h. At
this point, the vaporized FeCl3 exchanged with the H+ of zeolite according to the
reaction: FeCl3 (g) + H+zeol→[FeCl2]+zeol+HCl(g). An alkali solution was used to
neutralize HCl in the exhaust. After cooling with continuous flow of N2, the sample
was washed with deionized water and dried at 110oC overnight. Finally, the sample
was calcined at 600oC for 6 h in air.
Fe loading of the Fe-ZSM-5 was analyzed by Inductively Coupled Plasma Optical
Emission Spectrometer (ICP-OES) (PerkinElmer, OPTIMA 2000). For digestion, 50
mg sample was dissolved in a mixture of acids (HNO3: HCl: HF (v/v) = 5:1:1). The
mixture was placed in a water bath at 80 oC for 1h. For analysis, 1 ml H3BO3 saturated
solution was added to the residue of the dissolved mixture and filled up to 25 ml with
water.
2.
Figures S1-S5 and Table S1
S3
Figure S1 Experimental UV-Vis spectra and deconvoluted sub-bands of fresh and
Aged Fe-ZSM-5
Table S1. Percentage of the area of sub-bands derived by deconvolution of the UV-vis
DRS spectra: asubbands at λ≤ 300 nm, bsubbands at 300 nm <λ< 400 nm,
c
subbands atλ> 400 nm
Fresh Fe-ZSM-5
Aged Fe-ZSM-5
I1a (%)
I2b (%)
I3c (%)
41%
30%
28%
32%
31%
38%
I1, I2 and I3 represent the percentage of the species as isolated Fe3+ species (bands
below 300 nm), oligmeric clusters (between 300～400 nm) and Fe2O3 particles
(above 400 nm).
S4
Figure S2 Rate constant k for NO conversion at 190 oC-300oC in fast SCR reaction: (a)
NO2/NOx = 0.3 (b) NO2/NOx = 0.5
The reaction rate constant k was calculated according to the expressions below:
k =−
F
ln(1 − X )
W
Where k is the reaction rate constant based on mass of samples (cm3g-1s-1); F is the
volume flow rate (ml/S); W is the catalyst mass (g) and X is the fractional NO
conversion.
S5
Figure S3 comparison of fast SCR over fresh and hydrothermal aged Fe-ZSM-5
catalysts in fast SCR with NO2/NOx=0.3. (a) NO, NO2 and NH3 NOx conversion, (b)
N2O production. Reaction condition: 150 ppm NO2, 350 ppm NO, 500 ppm NH3, 5
vol.% O2, N2 balance; 50 mg catalyst, total flow of 500 ml/min and GHSV of 320 000
h-1.
S6
Figure S4 (a) NH3 consumption and twice NO consumption in fast SCR over fresh and aged
Fe-ZSM-5. (b) NO2 consumption unrelated to fast SCR over fresh and aged Fe-ZSM-5. reaction
condition: 250 ppm NO, 250 ppm NO2, 500 ppm NH3, 5 vol.% O2, N2 balance; 50 mg catalyst,
total flow of 500 ml/min and GHSV of 320 000 h-1.
S7
Figure S5 H2-TPR profiles of fresh and aged Fe-ZSM-5. Conditions: 10%H2/Ar,
heating ramp 20 oC/min.
S8