High temperature H2S selective oxidation on a copper-substituted hexaaluminate catalyst: A facile process for treating low concentration acid gas

Article abstract of DOI:10.1016/j.cclet.2021.07.053

H₂S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formation of SO₂ and catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction. Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCu_x, x = 0, 0.5, 1, 1.5, 2, 2.5) were prepared and investigated for the H₂S selective oxidation reaction at high temperature conditions (300-550°C). The LaCu₁ catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining H₂S and SO₂ in the tail gas.

Full text of DOI:10.1016/j.cclet.2021.07.053

Journal Pre-proof
High temperature H2S selective oxidation on a copper-substituted
hexaaluminate catalyst: A facile process for treating low
concentration acid gas
Xin Xu , Ganggang Li , Fenglian Zhang , Guoxia Jiang ,
Zhengping Hao
PII:
DOI:
Reference:
S1001-8417(21)00553-2
https://doi.org/10.1016/j.cclet.2021.07.053
CCLET 6562
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Chinese Chemical Letters
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Accepted date:
29 April 2021
5 June 2021
24 July 2021
Please cite this article as: Xin Xu , Ganggang Li , Fenglian Zhang , Guoxia Jiang , Zhengping Hao ,
High temperature H2S selective oxidation on a copper-substituted hexaaluminate catalyst: A
facile process for treating low concentration acid gas, Chinese Chemical Letters (2021), doi:
https://doi.org/10.1016/j.cclet.2021.07.053
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Communication
High temperature H2S selective oxidation on a copper-substituted
hexaaluminate catalyst: A facile process for treating low
concentration acid gas
Xin Xua,b, Ganggang Lia,b, Fenglian Zhangb,**, Guoxia Jiangb, Zhengping Haoa,b,*
aResearch Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
bNational Engineering Laboratory for VOCs Pollution Control Material & Technology, Research Center for Environmental
Material and Pollution Control Technology, University of Chinese Academy of Sciences, Beijing 101408, China
Corresponding authors: Tel: 86-10-69672982 (Z. Hao)
**86-10-69672977 (F. Zhang).
zphao@ucas.ac.cn (Z. Hao)
zhangfenglian@ucas.ac.cn (F. Zhang).
1

Abstract
H2S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas
with simple process operation and low investment. However, undesirable results such as large formation of SO2 and
catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction.
Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently
needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCux, x = 0, 0.5, 1, 1.5, 2, 2.5) were
prepared and investigated for the H2S selective oxidation reaction at high temperature conditions (300-550 °C). The
LaCu1 catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive
properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining
H2S and SO2 in the tail gas.
Keywords
low concentration acid gas; H2S selective oxidation; high temperature; hexaaluminate catalyst
H2S-containing acid gas that are generated in large amount from the fossil energy processing industry,
constitute a major hazard to human health and the environment [1]. An increase in utilization of high-sulfur
raw materials and the enforcement of stringent environmental regulations have triggered demand for
achieving a higher level of acid gas removal and its efficient treatment [2].
At present, the high concentration of H2S (≥ 12 vol%) is mainly treated by the Claus process, which
consists of a high-temperature (1000-1400 °C) thermal section and a low-temperature multistage catalytic
section. However, the Claus reaction is restricted by thermodynamic equilibrium, and 3-5 vol% H2S gas will
be remained in the Claus tail gas [3]. Several technologies exist for the treatment of Claus tail gas, including
low-temperature Claus reaction technology, reduction-absorption technology, and H2S selective catalytic
oxidation technology. Among them, H2S selective catalytic oxidation technology is widely concerned
because it is not limited by the thermodynamics and H2S concentration, and that low operating cost is needed.
The reaction equations are as follows (R1, with side reactions R2 and R3). Recently, a lot of processes have
been developed based on this reaction, such as SuperClaus, EuroClaus, Clinsulf-Do, Modop and Selectox
technologies [4].
H2S + 1/2 O2 → 1/n Sn + H2O,
1/n Sn + O2 → SO2
H2S + 3/2 O2 → SO2 + H2O
∆H = 222 kJ/mol
(R1)
(R2)
(R3)
Additionally, in coal chemical industry and some small-scale refineries, such as coking plants, fertilizer
plants, the concentration of byproduct H2S is relatively low (< 12 vol%). The acid gas is not suitable to be
treated by the Claus process because of its low calorific value. Use of auxiliary fuel must be taken in order to
maintain a stable flame of high temperature and achieve good combustion efficiency, which complicates the
process and increases capital cost. Methods based on absorption and adsorption are alternatives for the
treatment of low concentration H2S acid gas. However, the absorbents or adsorbents need periodic
regeneration and the desorbed H2S still needs further processing [5]. H2S selective oxidation technology can
not only be applied to the Claus tail gas, but also for the treatment of low concentration H2S acid gas. More
importantly, compared to the traditional absorption and adsorption method, H2S selective oxidation could
oxidize H2S to element sulfur directly and continuously, achieving cleaner and more sustainable production
[6].
Catalysts play an important role in selective oxidation of H2S, which the H2S conversion and sulfur
selectivity both depend on the performance of the catalysts. However, the selective oxidation of H2S is a
strong exothermic reaction (∆H = 222 kJ/mol), and reacting every 1 vol% H2S will lead to a 50-60 °C
temperature rise of the fixed reaction bed [7]. Meanwhile, the high formation activation energy of SO2 (120
kJ/mol) determines that high temperature is conducive to the generation of SO2 [8]. To maintain a long
catalytic life and high sulfur selectivity, recent researches generally concern the reaction temperature at
160-300 °C. The catalysts mainly concentrate on the iron-, vanadium-, and cadmium- based catalysts, which
might be overactive to cause the overoxidation of reactant H2S or product S into SO2. Moreover, metal
oxides are easy to be vulcanized by H2S under high temperature conditions [9-11]. The narrow activity
window of existing catalysts limits the further application of H2S selective oxidation technology. The high
temperature reaction puts forward requirements for the anti-sintering and anti-poisoning properties of
catalytic materials. Moreover, side reactions and by-product SO2 will be conducive to generate with the
increase of bed temperature. Therefore, it is meaningful and urgent to develop a high temperature resistant
2

catalyst for H2S selective oxidation reaction, which could maintain the high activity and high sulfur
selectivity simultaneously.
Hexaaluminate is a class of aluminate compounds with hexagonal layered crystal structure. The general
formula can be expressed as ABxAl12-xO19. The A site and B site (Al3+ ions) in the crystal lattice could be
substituted by metal ions with similar radius [12]. Furthermore, the special layered structure with alternate
Al2O3 spinel phases separated by mirror planes is mainly responsible for their excellent anti-sintering ability
and thermal stability [13]. Consequently, hexaaluminate with sufficient redox and acid-base surface
properties can be achieved and are adaptable for many catalytic reactions. As a preferred oxygen diffusion
channel, the mirror layer has a great application prospect in the field of oxygen involved reactions [14]. In
recent years, hexaaluminate materials have attracted a lot of attention for their application in high
temperature reactions, for example, catalytic combustion of methane and selective catalytic oxidation of
ammonia [15-18]. The selective oxidation of H2S at high temperature conditions requires the catalyst that on
the one hand has active sites to selectively oxidize H2S into elemental sulfur, and on the other hand has
prominent stability to prevent it from being vulcanized at high temperature. Based on this, the hexaaluminate
materials maybe a promising and potential catalytic material for H2S selective oxidation at high temperature.
Thus, a series of copper substituted LaCuxAl12-xO19 (LaCux, x = 0, 0.5, 1, 1.5, 2, 2.5) hexaaluminate
catalysts were synthesized with a pH-controlled coprecipitation method and their catalytic performance for
H2S selective oxidation reaction were investigated at high temperature conditions (300-550 °C). The
physicochemical properties of LaCuxAl12-xO19 catalysts were characterized by various techniques and the
details about catalysts preparation, characterization, and evolution tests were described in the Supporting
information experimental section. For convenience, all catalysts were named as LaCux, such as LaCu0
represented LaAl12O19 and LaCu1 represented LaCu1Al11O19.
Firstly, the structure and textural properties of LaCux (x = 0, 0.5, 1, 1.5, 2, 2.5) catalysts were studied by
X-ray diffraction (XRD) and N2 adsorption-desorption measurements and the results are shown in Fig. 1 and
Table S1 (Supporting information). As seen in Fig. 1a, all catalysts exhibited standard magneto-plumbite
type hexaaluminate diffraction peaks (MP, JCPDS No. 33-0699). The diffraction peaks were very sharp and
there was no other impurity structure detected, indicating the hexaaluminate crystal phase formed completely
after calcination at 1200 °C. Compared with the XRD pattern of LaCu0 catalyst, the peaks of
copper-substituted catalysts were sharper. It is also mentioned in the literature that the substitution of
transition metal contributes to the formation of hexaaluminate crystal phase [19]. Furthermore, as shown in
Fig. 1b, with the increase of Cu doping amount, the peaks shifted progressively towards lower angle. This
behavior is mainly due to the distortion of crystal lattice after Cu2+ with larger radius replacing the smaller
Al3+ ion, which further confirms that Cu2+ was almost doped into the crystal structure of hexaaluminate and
partly replaced the position of Al3+.
Fig. 1c shows that all catalysts exhibited a characteristics of type IV isotherms with obvious hysteresis
loops, implying a mesoporous structure with good pore connectivity of the catalysts [20]. Among these
catalysts, the LaCu0, LaCu0.5 and LaCu1 catalysts displayed obvious hysteresis loops, which might contribute
to a better pore structure connectivity. Besides, the pore size of the catalysts from Fig. 1d mainly distributed
between 20-100 nm. The pore size distribution was relatively broad, indicating a variety of different size
mesoporous structures. Furthermore, the specific surface area, pore volume and average pore diameters of
the catalysts are also given in Table S1 (Supporting information). As shown, the specific surface area of the
catalysts almost decreased with the increase of Cu doping amount. Particularly, the LaCu1 catalyst had a
large pore volume (0.16 cm3/g) and average pore diameter (27.8 nm). Since the mesoporous structure is
conducive to the diffusion of reactant molecule and could facilitate it accessible to the active phase, the
larger pore volume and pore size would be benefit for the catalytic performance [21].
3


(a)

Hexaaluminate

(b)






LaCu2.5
LaCu2









LaCu2.5
LaCu2
LaCu1.5
LaCu1


LaCu1.5
LaCu1
LaCu0.5
LaCu0.5
LaCu0
LaCu0
10 20 30 40 50 60 70 80 31.0
2 Theta (degree)
31.5
32.0
32.5
33.0
2 Theta (degree)
LaCu0.5
(c)
(d)
LaCu2.5
LaCu1
LaCu1.5
LaCu2
LaCu2.5
LaCu0
LaCu2
LaCu1.5
LaCu1
LaCu0.5
LaCu0
0.0
0.2
0.4
0.6
0.8
1.0
10
100
Relative pressure (P/P0)
Pore diameter (nm)
Fig. 1. XRD patterns (a, b), N2 adsorption-desorption isotherms (c) and pore size distribution (d) profiles of LaCux (x = 0, 0.5, 1,
1.5, 2, 2.5) catalysts.
The catalytic performance of H2S selective oxidation reaction on LaCux (x = 0, 0.5, 1, 1.5, 2, 2.5)
catalysts were investigated and the results are shown in Fig. 2. As seen in Fig. 2a, the H2S conversion of
different Cu doping amount catalysts quite varied at 300 °C. The order is as follows: LaCu1 > LaCu0.5
>
LaCu2.5 > LaCu0 > LaCu2 > LaCu1.5. When the temperature was above 350 °C, there were little differences in
activity and all catalysts tended to a similar change trend. At first, the H2S conversion decreased with the
temperature rising to 450 °C and then it was a slight increase up to 550 °C. Among these catalysts, the LaCu1
catalyst displayed the highest H2S conversion, about 91.5% at 300 °C, and more than 80% even at 450 °C. In
terms of sulfur selectivity (Fig. 2b), the variation of different Cu doping amount catalysts is basically similar.
The sulfur selectivity decreased firstly with the temperature rising from 300 °C to 450 °C, and then increased
slightly up to 550 °C. Overall, almost all the catalysts can achieve more than 86% sulfur selectivity at the
investigated temperature ranges except for LaCu0 catalyst. Combined with the activity results of different
transition metal substituted LaB (B = Fe, Co, Ni, Cu, Mn) catalysts as presented in Fig. S1 (Supporting
information), it can be inferred that the transition metal substituted of hexaaluminate could improve the
catalysts performance for H2S selective oxidation. Particularly, the stability behavior of LaCu1 catalyst for
H2S selective oxidation at 550 °C was also investigated. As shown in Fig. S2 (Supporting information), the
catalyst could operate steadily for 48 h at a high temperature of 550 °C almost without any loss of activity,
displaying a high thermal reaction stability.
98
96
94
92
90
88
86
84
82
94
92
90
88
86
84
82
80
78
76
74
LaCu0
LaCu0.5
LaCu1
LaCu1.5
LaCu2
LaCu2.5
LaCu
0
(a)
(b)
LaCu
0.5
LaCu
1
LaCu
1.5
LaCu
2
LaCu
2.5
300 350 400 450 500 550
Temperature(ºC)
300 350 400 450 500 550
Temperature (ºC)
Fig. 2. H2S conversion (a) and sulfur selectivity (b) on LaCux (x = 0, 0.5, 1, 1.5, 2, 2.5) catalysts. (Reaction conditions: T =
300-550 °C, GHSV = 5000 h1, [H2S] = 5000 ppm, [O2] = 2500 ppm).
The chemical properties of catalyst are significant for the catalytic performance. In view of this, various
methods were adopted to explore the chemical status of the active species. X-ray photoelectron spectroscopy
(XPS) was employed to characterize the chemical status of the transition metals. The Cu 2p XPS spectra of
the catalysts are presented in Fig. 3. According to the literature, the peaks at 935.8 eV and 955.1 eV are the
signal peaks of Cu 2p3/2 and Cu 2p1/2, respectively, showing a 19.9 eV spin-orbit splitting and the signal
peaks near 945 eV and 965 eV are satellite peaks of Cu 2p. It is well known that shake-up peaks of Cu-XPS
4

are present in the spectra of d9 Cu2+-containing samples but are absent in d10 Cu+ spectra [22]. Thus, the Cu
species mainly existed in the form of Cu2+ in the hexaaluminate crystal structure. Moreover, the peaks of Cu
2p3/2 could be deconvoluted into two main contributions located around 933.6 eV and 935.2 eV, ascribed to
Cu2+ in the tetrahedral and octahedral coordination, respectively [23]. The UV-vis diffuse reflectance spectra
were performed to obtain detailed information on the oxidation state and coordination of Cu species. As
shown in Fig. S3 (Supporting information), two characteristic bands were observed. According to previously
published reports, the absorption band at 210-320 nm results from the O2 → Cu2+ charge transfer, while the
broad band at 600-800 nm were associated with Cu2+ in an octahedral configuration, more or less
tetragonally [24]. Therefore, the results of XPS and UV-vis DRS implied that Cu2+ ions were existed in
tetragonal and tetragonally distorted octahedral sties of the hexaaluminate catalysts.
Cu 2p
Cu 2p3/2
Shake-up
Cu 2p1/2
Cu 2p3/2
Shake-up
LaCu2.5
LaCu2.5
LaCu2
LaCu2
LaCu1.5
LaCu1
LaCu1.5
LaCu1
LaCu0.5
LaCu0.5
930 935 940 945 950 955 960 965
Binding energy (eV)
930
935
940
945
950
Binding energy (eV)
Fig. 3. XPS spectra of LaCux (x = 0.5, 1, 1.5, 2, 2.5) catalysts.
As known, the reducibility of catalyst plays a vital role in the catalytic performance especially in the
oxidation reactions. Therefore, the reductive properties of LaCux (x = 0.5, 1, 1.5, 2, 2.5) catalysts were
studied by the H2 temperature-programmed reduction (H2-TPR) experiments. Fig. 4 shows the H2-TPR
profiles of hexaaluminate catalysts with different Cu doping amount. The major reduction peaks were all
below 600 °C. It is well known that different positions of the reduction peaks indicate the different
reducibility, while the positions of the reduction peaks might be ascribed to the valence state changes and the
difference in the crystallographic sites of metal ions [24]. Researchers generally believe that the
crystallographic positions (octahedral sites) located near the mirror layer are easier to be reduced [25]. Based
on this, the major reduction peaks appearing at 200-350 °C were ascribed to the reduction of Cu2+ in the
substituted positions of Al3+. Moreover, the different reduction temperature might be due to the different
crystallographic positions of Cu2+, tetragonal or octahedral sties as mentioned in XPS analysis. In addition,
with the Cu doping amount greater than 1.5, the catalysts showed a small reduction peak at 100-200 °C,
especially for the LaCu2.5 catalyst. The peaks could be ascribed to the reduction of Cu2+ in the copper oxides,
which indicates that the amount of Cu doping in the crystal structure of hexaaluminate is limited, and
excessive Cu doping will lead to the form of the amorphous copper oxides.
148 ºC
LaCu2.5
LaCu2
LaCu1.5
300 ºC
LaCu1
LaCu0.5
100 200 300 400 500 600 700
Temperature (ºC)
Fig. 4. H2-TPR profiles of LaCux (x = 0.5, 1, 1.5, 2, 2.5) catalysts.
According to the above physicochemical analysis, the LaCu1 catalyst displayed the best reductive
properties, which was due to the reason that the appropriate Cu doping amount provides a proper proportion
of Cu2+ in tetragonal or octahedral sties. Moreover, combined with the physical N2 adsorption-desorption
measurements, the LaCu1 catalyst has a large specific surface area and pore structure, which is conducive to
the diffusion of reactant molecule. Therefore, it indicated that excellent reducibility resulted from a proper
5

substitution of Cu and more accessible of reactant molecule owing to the textual properties are responsible
for highest reactivity of LaCu1 catalyst. While for the catalysts with the Cu doping greater than 1.5, there
were small decline in catalytic activity, might because of the inferior reducibility, less pore structures and the
form of amorphous copper oxides with excess Cu substituted amount.
Although the copper-substituted hexaaluminate catalysts exhibited excellent catalytic activity, it still
cannot achieve 100% H2S conversion and sulfur selectivity unfortunately. In order to get a better sulfur yield,
two facile deep processing paths are proposed for the treatment of the tail gas which includes the remaining
H2S and SO2 generated in the reaction. The processes are presented in Scheme S1 (Supporting information).
As shown, one deep processing is that firstly convert the generated SO2 to H2S through a hydrogenation
method, then eliminate the H2S completely by a traditional H2S selective oxidation technology (generally at
low temperature conditions). Another path is to eliminate H2S and SO2 directly by adopting the catalytic
section of Claus process, because the ratio of H2S and SO2 concentration in the tail gas is close to 2:1, which
is suitable for the Claus reaction (2H2S + SO2 → 3/n Sn + 2H2O).
In summary, the copper-substituted hexaaluminate catalysts exhibited excellent catalytic performance
and great thermal reaction stability for H2S selective oxidation. Among these catalysts, the LaCu1 catalyst
showed the best H2S conversion (91.1%, 300 °C) and sulfur selectivity (93.7%, 300 °C), and can maintained
them at 82.5% and 87% respectively even at 550 °C. Hexaaluminate materials have excellent thermal
stability because of its special hexagonal layered structure which make LaCu1 catalyst stable during the high
temperature reaction, almost operating steadily for 48 h at 550 °C without any loss of activity. Moreover, the
appropriate Cu doping amount provides a proper proportion of Cu2+ in tetragonal or octahedral sties and a
larger specific surface area and pore structure, which improve the reductive properties of the LaCu1 catalyst.
Besides, two facile deep processing paths are proposed for the treatment of the low concertation H2S acid
gas completely. The technology could reduce the process operation and equipment investment, which has a
good application prospect in the field of industrial acid gas treatment.
6

Declaration of competing interest
The authors report no declarations of interest.
Acknowledgments
This work was financially supported by the National Natural Science Foundation of China (Nos.
21976176, 22006148), the Key R&D Program of Shandong province (No. 2019JZZY010506) and the
Fundamental Research Funds for the Central Universities.
7

References
[1] R.A. Pandey, S. Malhotra, Crit. Rev. Environ. Sci. Technol. 29 (1999) 229-268.
[2] A.K. Gupta, S. Ibrahim, A.A. Shoaibi, Prog. Energy Combust. Sci. 54 (2016) 65-92.
[3] A. PiÉPlu, O. Saur, J.C. Lavalley, O. Legendre, C. NÉdez, Catal. Rev. Sci. Eng. 40 (1998) 409-450.
[4] A.D. Wiheeb, I.K. Shamsudin, M.A. Ahmad, et al., Rev. Chem. Eng. 29 (2013) 449-470.
[5] M.S. Shah, M. Tsapatsis, J.I. Siepmann, Chem. Rev. 117 (2017) 9755-9803.
[6] A.P. Reverberi, J.J. Klemeš, P.S. Varbanov, B. Fabiano, J. Clean. Prod. 136 (2016) 72-80.
[7] P. Nguyen, D. Edouard, J.M. Nhut, et al., Appl. Catal. B 76 (2007) 300-310.
[8] M. Steijns, F. Derks, A. Verloop, P. Mars, J. Catal. 42 (1976) 87-95.
[9] T.N. Mashapa, J.D. Rademan, M.J. Janse van Vuuren, Ind. Eng. Chem. Res. 46 (2007) 6338-6344.
[10] B. Pongthawornsakun, S. Phatyenchuen, J. Panpranot, P. Praserthdam, J. Environ. Chem. Eng. 6 (2018) 1414-1423.
[11] J.H. Uhm, M.Y. Shin, J. Zhidong, J.S. Chung, Appl. Catal. B 22 (1999) 293-303.
[12] Y.Y. Zhu, Z.Y. Yue, W. Bian, et al., Prog. Chem. 30 (2018) 1992-2002.
[13] M. Tian, X.D. Wang, T. Zhang, Catal. Sci. Technol. 6 (2016) 1984-2004.
[14] M. Machida, K. Eguchi, H. Arai, J. Catal. 120 (1989) 377-386.
[15] L. Lietti, C. Cristiani, G. Groppi, P. Forzatti, Catal. Today 59 (2000) 191-204.
[16] R. Kikuchi, Y. Iwasa, T. Takeguchi, K. Eguchi, Appl. Catal. A Gen. 281 (2005) 61-67.
[17] S.M. Zhu, X.D. Wang, A.Q. Wang, Y. Cong, T. Zhang, Chem. Commun. 17 (2007) 1695-1697.
[18] P. Artizzu-Duart, Y. Brullé, F. Gaillard, et al., Catal. Today 54 (1999) 181-190.
[19] G. Groppi, C. Cristiani, P. Forzatti, J. Catal. 168 (1997) 95-103.
[20] X.H. Zheng, X.H. Chen, J.B. Chen, Y. Zheng, L.L. Jiang, Chem. Eng. J. 297 (2016) 148-157.
[21] X. Gong, W.W. Wang, X.P. Fu, et al., Fuel 229 (2018) 217-226.
[22] X.H. Zheng, Y.L. Li, S.J. Liang, et al., J. Catal. 389 (2020) 382-399.
[23] Q.G. Zhai, S.J. Xie, W.Q. Fan, et al., Angew. Chem. Int. Ed. 52 (2013) 5776-5779.
[24] G.X. Jiang, F.L. Zhang, Z. Wei, et al., Catal. Sci. Technol. 10 (2020) 1477-1491.
[25] S. Laassiri, N. Bion, D. Duprez, H. Alamdari, S. Royer, Catal. Sci. Technol. 3 (2013) 2259-2269.
Graphical abstract
The copper-substituted hexaaluminate catalyst (LaCu1) exhibited excellent catalytic performance and
reaction stability for the high temperature H2S selective oxidation. And two facile deep processing paths
are proposed for the complete treatment of low concentration acid gas.
8