Mn-based Catalysts Research Articles

Important factors of the A-site deficient Mn perovskites design affecting the CO oxidation activity

A-site deficient La0.4Sr0.4MnxTi1−xO3 (LSMT, x = 0, 0.4, 0.6, 0.8) perovskites were investigated for their structural change and effect on CO oxidation activity. The XRD, XPS, TPR and O2-TPD analysis represent the change in Mn concentration, known as an active species in oxidation, affecting the crystal structure, oxidation state of the B-site cation (Mn), number of oxygen vacancies, and the reducibility of the catalysts. The shift in the main perovskite diffraction peak in XRD spectra of the perovskites with a change in Mn content represents the formation of cationic vacancies. At the lower temperature (<200 oC), CO oxidation efficiency of LSMT perovskite catalysts was found to be almost identical. This can be attributed to their similar perovskite structure and surface area. Compared to the higher temperature (>200 oC) CO oxidation activity, the LSMT catalyst with lower Mn content of 0.4 shows relatively better performance than the higher Mn content samples, which signifies the active role of the Mn oxidation state and lattice oxygen species of the perovskite catalysts. Moreover, the LSMT4446 catalyst shows stable activity for more than 12 h with an average CO conversion of 80 %. From these results, we found that the factors of the Mn oxidation state and the type of oxygen species are crucial when designing an Mn-based perovskite catalyst for catalytic applications.

Degradation of dimethyl phthalate by morphology controlled β-MnO2 activated peroxymonosulfate: The overlooked roles of high-valent manganese species

Activated peroxymonosulfate (PMS) processes have emerged as an efficient advanced oxidation process to eliminate refractory organic pollutants in water. This study synthesized a novel spherical manganese oxide catalyst (0.4KBr-β-MnO2) via a simple KBr-guided approach to activate PMS for degrading dimethyl phthalate (DMP). The 0.4KBr-β-MnO2/PMS system enhanced DMP degradation under different water quality conditions, exhibiting an ultrahigh and stable catalytic activity, outperforming equivalent quantities of pristine β-MnO2 by 8.5 times. Mn(V) was the dominant reactive species that was revealed by the generation of methyl phenyl sulfone from methyl phenyl sulfoxide oxidation. The selectivity of Mn(V) was demonstrated by the negligible inhibitory effects of Inorganic anions. Theoretical calculations confirmed that Mn (V) was more prone to attack the CO bond of the side chain of DMP. This study revealed the indispensable roles of high-valent manganese species in DMP degradation by the 0.4KBr-β-MnO2/PMS system. The findings could provide insight into effective PMS activation by Mn-based catalysts to efficiently degrade pollutants in water via the high-valent manganese species.

Study on the Reaction Performance of Ce- and Co-Modified Mn-Based Catalysts in C3H6-SCR

Study on the Reaction Performance of Ce- and Co-Modified Mn-Based Catalysts in C₃H₆-SCR

High efficient manganese‑nitrogen co-doped lignin-based carbon catalysts to activate peroxymonosulfate for the degradation of bisphenol A

Mn-based catalysts have attracted widespread attention because of their low price, sufficient source and effective activation of peroxymonosulfate (PMS) to generate free radicals for rapid degradation of organic pollutants. In most pulp and paper industries, lignin sulfonates are usually the waste streams or serve as low-value fuels. However, lignin sulfonates due to its abundant aromatic structure and sulfur functional groups, is regarded as an excellent carbon resource. The stability of supported Mn-based catalyst can be improved by doping nitrogen atoms through the formation of covalent bonds. In this work, Mn, N co-doped carbon composites were prepared by one-step carbonization, and the catalysts were characterized by TEM, XRD, XPS, etc. and the results show that the catalysts with low Mn content mainly contain highly dispersed Mn species such as MnNx species, while high Mn loading catalyst includes some MnOx species. The catalytic performances of the catalysts were evaluated by the degradation of bisphenol A (BPA) by activating PMS, which can reach >95 % in 8 min. Catalyst recyclability experiments demonstrate that carbon-based materials have good stability without the remarkable leaching of metal ions during the degradation reaction. The results of radical capture experiments and radical-assisted ESR show that the active species of the reaction is non-free radical singlet oxygen (1O2), which can effectively degrade BPA. This study provides a facile and efficient method to prepare high-efficient Mn-N-C catalysts in the catalytic decomposition of BPA.

Quantifying the Two-Dimensional Driving Patterns of Chemisorbed Oxygen and Particle Size on NO Reduction Activity and Mechanism.

Quantification in the driving patterns of activity descriptors on structure-activity relationships and reaction mechanisms over heterogeneous catalysts is still a great challenge and needs to be addressed urgently. Herein, with the example of typical Mn-based catalysts, based on the activity regularity and many characterizations, the chemisorbed oxygen density (ρOβ) and particle size (dTEM) have been proposed as the two-dimensional descriptors for selective catalytic reduction of NO, whose role is in quantifying the contents of vacancy defects and the amounts of active sites located on terraces or interfaces, respectively. They can be utilized to construct and quantify the driving patterns for the structure-activity relationships and reaction mechanisms of NO reduction. As a consequence, a complementary modulation for Ea by ρOβ and dTEM is described quantitatively in terms of the fitted functions. Moreover, based on the structure-activity relationships and the quantification laws of in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), the reaction efficiency (RE) of the specific combined NOx-intermediate is identified as the trigger to drive the Langmuir-Hinshelwood mechanism and modulated by the descriptors complementally and collaboratively following the fitted quantification functions. Either of the two descriptors at its lower values plays a dominant role in regulating Ea and RE, and the dominant factor evolves progressively: dTEM ↔ coupling dTEM with ρOβ ↔ ρOβ, when the dependency of Ea and RE on the descriptors is adopted to identify the dominant factor and domains. Therefore, this work has quantitatively accounted for the essence of activity modulation and may provide insight into the quantitative driving patterns for reaction activity and mechanism.

Research Progress on Metal Oxides for the Selective Catalytic Reduction of NOx with Ammonia

Nitrogen oxides emitted from diesel vehicle exhaust seriously endanger the atmospheric environment and human health, which have attracted people’s attention. Among numerous nitrogen oxide (NOx) removal technologies, photocatalytic removal of NOx and SCR have received widespread attention. The photocatalytic treatment of NOx technology is a good choice due to its mild reaction conditions and low costs. Moreover, NH3-SCR has been widely used in denitration technology and plays an important role in controlling NOx emissions. In NH3-SCR technology, the development of high-efficiency catalysts is an important part. This paper summarizes the research progress of metal oxide catalysts for NH3-SCR reactions, including V-based catalysts, Mn-based catalysts, Fe-based catalysts, Ce-based catalysts, and Cu-based catalysts. Meanwhile, the detailed process of the NH3-SCR reaction was also introduced. In addition, this paper also describes a possible SO2 poisoning mechanism and the stability of the catalysts. Finally, the problems and prospects of metal oxide catalysts for NOx removal were also proposed.

Low temperature oxidation of o-xylene by Mn-based catalysts prepared by hydrothermal calcination: Influence mechanism of complicated flue gas components and intermediate product

Catalytic oxidation technology has proven to be an effective method for purifying flue gas of CFPPs. However, conventional catalysts face limitations such as limited activity and vulnerability to contamination from SO2 and H2O. This study aims to assess the efficiency of a newly synthesized Mn-based catalyst, prepared via a hydrothermal-calcination technique, in removing VOCs from simulated coal combustion flue gas. The results demonstrate that the catalyst produced through hydrothermal synthesis, followed by calcination at 400 °C, exhibits a catalytic oxidation efficiency of 96.2% for VOCs at 350 ℃. Furthermore, the catalyst demonstrates anti-poisoning properties. To gain a deeper understanding, we utilized DRIFTS to investigate the mechanism of o-xylene adsorption on the catalyst surface, reaction conversion intermediates, and the influence of complex flue gas components (NH3, NO, and SO2) on the catalytic reaction process. Our investigation provides insight in the improvement of Mn-based catalysts for the removal of VOCs from coal flue gas.

Transition metal modified Mn-based catalysts for CO-SCR in the presence of excess oxygen

The CO-SCR technology based on transition metal is of great significance for NOx removal in large-scale industrial production. However, excess oxygen usually hinders the deNOx reaction in the actual industrial process. In this paper, a series of Mn-based catalysts modified by transition metals (Fe, Ni, Cu) were prepared using the co-precipitation method, which aimed to obtain good CO-SCR performance under O2-rich condition. The results showed that the Cu-Mn2 sample exhibited excellent deNOx performance. Regardless of the presence or absence of oxygen, the NO conversion of Cu-Mn2 catalyst was remain about 60% and 95% at 350 and 400 ℃, respectively. Differently, the NO conversion of Fe-Mn2 catalyst significantly increased from approximately 10% to 61% at 400 ℃ after introducing oxygen, which proved that excess oxygen could promote the CO-SCR process over Fe-Mn2 sample. The varied physical and chemical properties of the prepared materials were thoroughly evaluated through BET, SEM, XRD, XPS and in situ DRIFTS technologies. The results demonstrated that perovskite α-Mn2O3, decahedral Mn5O8, Fe2O3 and Fe3O4 crystals were the dominant structures promoting deNOx reaction on the Fe-Mn2 catalyst. The oxidation of low valence nitrogen oxides by decahedral Mn5O8 on Fe-Mn2 catalyst was an important factor for oxygen resistance. And the various spinel structures over Ni-Mn2, and Cu-Mn2 indicated strong synergistic effects. For the Cu-Mn2 catalyst, the strong synergistic effect of Cu-□-Mn species could promote the dissociation of intermediate -NONO. O2 tended to occupy the surface synergetic oxygen vacancies in Cu-□-Mn species at high temperatures, which could inhibit the dissociation of -NONO and enhance the CO oxidation reaction. The possible reaction mechanisms for CO-SCR over Mn-based catalysts were discussed specifically.

Unveiling the SO2 Resistance Mechanism of a Nanostructured SiO2(x)@Mn Catalyst for Low-Temperature NH3-SCR of NO.

Low N2 selectivity and SO2 resistance of Mn-based catalysts for removal of NOx at low temperatures by NH3-SCR (selective catalytic reduction) technology are the two main intractable problems. Herein, a novel core-shell-structured SiO2@Mn catalyst with greatly improved N2 selectivity and SO2 resistance was synthesized by using manganese carbonate tailings as raw materials. The specific surface area of the SiO2@Mn catalyst increased from 30.7 to 428.2 m2/g, resulting in a significant enhancement in NH3 adsorption capacity due to the interaction between Mn and Si. Moreover, the N2O formation mechanism, the anti-SO2 poisoning mechanism, and the SCR reaction mechanism were proposed. N2O originated from the reaction of NH3 with O2 and the SCR reaction, as well as from the reaction of NH3 with the chemical oxygen of the catalyst. Regarding improving the SO2 resistance, DFT calculations showed that SO2 was observed to preferentially adsorb onto the surface of SiO2, thus preventing the erosion of active sites. Adding amorphous SiO2 can transform the reaction mechanism from Langmuir-Hinshelwood (L-H) to Eley-Rideal (E-R) by adjusting the formation of nitrate species to produce gaseous NO2. This strategy is expected to assist in designing an effective Mn-based catalyst for low-temperature NH3-SCR of NO.

Boosting Water-Resistance Ability on a PTFE Modified Ti-OMS-2 Catalyst for Low-Temperature NH3-SCR Reaction

Manganese-based catalysts are considered as ideal alternative catalysts for NH3 selective catalytic reduction of NOx due to their excellent denitrification performance, but their weak water resistance limits industrial applications. To improve the water resistance of low-temperature Mn-based catalysts in the NH3-SCR reaction, a Ti-OMS-2 (titanium-manganese oxide octahedral molecular sieve) catalyst was prepared by the hydrothermal method, and polytetrafluoroethylene (PTFE) powder was methodically introduced on the catalyst surface by the impregnation method. Importantly, the introduction of PTFE on the Ti-OMS-2 catalyst surface could effectively inhibit the adsorption of water molecules and reduce the probability of active species being consumed. Thus, it showed better catalytic activity and water resistance. The activity of the Ti-OMS-2-20%-PTFE catalyst could reach more than 80% when water vapor was introduced at 180 °C. More importantly, the Ti-OMS-2-20%-PTFE catalyst did not readily bind the active species (Mn4+ and Oads) and maintained the adsorption and activation of NH3 species. Moreover, it was easy for PTFE to form a weak surface hydrophobic layer on the Ti-OMS-2 catalyst surface that could effectively inhibit water toxicity. Therefore, this work provided a reasonable idea and experimental accumulation for the industrial application of Mn-based catalysts.

Graphene Oxide Addition Induces the Improvement of ORR Catalysis Properties of Low-Cost Mn-Based Catalyst Used for Al-Air Battery

To further improve the oxygen reduction reaction (ORR) activity of low-cost Mn based catalyst, graphene oxide (GO) was added in the preparation of one dimensional (1D) α-MnO2 nanorod using KMnO4-MnSO4 system via hydrothermal method. Experimental results showed that the GO addition (20 wt%) could induce the formation of MnO(OH) nanorod. The Mn based@GO catalyst had more surface defects and oxygen vacancies compared with pure α-MnO2. The onset potential, half-wave potential (E1/2) and limiting current density were significantly enhanced from 0.86 V/0.66 V/3.56 mA cm-2 to 0.91 V/0.77 V/5.41 mA cm-2, indicating that GO addition could greatly improve the catalytic activity of Mn based catalyst. Furthermore, the discharge voltage, power density, mass energy density of Al-air battery using Mn based@GO catalyst were greatly improved comparing with the usage of pure MnO2 catalyst, and it was also found that the application effect of Mn based @GO catalyst in the Al-air battery was almost comparable to the commercial 20% Pt/C catalyst. Our research revealed for the first time the commercial potential of the novel and low-cost MnO2/MnO(OH)@GO nanocomposite in the Al-air battery.

Permanganate activation with Mn oxides at different oxidation states: Insight into the surface-promoted electron transfer mechanism

The development of new strategies to improve the removal of organic pollutants with permanganate (KMnO4) is a hot topic in water treatment. While Mn oxides have been extensively used in Advanced Oxidation Processes through an electron transfer mechanism, the field of KMnO4 activation remains relatively unexplored. Interestingly, this study has discovered that Mn oxides with high oxidation states including γ-MnOOH, α-Mn2O3 and α-MnO2, exhibited excellent performance to degrade phenols and antibiotics in the presence of KMnO4. The MnO4- species initially formed stable complexes with the surface Mn(III/IV) species and showed an increased oxidation potential and electron transfer reactivity, caused by the electron-withdrawing capacity of the Mn species acting as Lewis acids. Conversely, for MnO and γ-Mn3O4 with Mn(II) species, they reacted with KMnO4 to produce cMnO2 with very low activity for phenol degradation. The direct electron transfer mechanism in α-MnO2/KMnO4 system was further confirmed through the inhibiting effect of acetonitrile and the galvanic oxidation process. Moreover, the adaptability and reusability of α-MnO2 in complicated waters indicated its potential for application in water treatment. Overall, the findings shed light on the development of Mn-based catalysts for organic pollutants degradation via KMnO4 activation and understanding of the surface-promoted mechanism.

Insight into the temperature-dependent SO2 resistance over Mn-based de-NOx catalyst

Herein, two simple model catalysts (Mn3O4 and MnFeOx) were fabricated and operated under different temperatures (100, 150, 200, 250 °C) in SCR atmosphere with the presence of SO2, followed by thermal regeneration and characterizations to reveal the deactivation mechanism and the role of FeOx. The results indicated both catalysts exhibited temperature-dependent deactivation behavior, where the total activity loss displayed volcano-type SO2 resistance tendency within 100–250 °C and the most severe activity loss (98 % for Mn3O4 and 81 % for MnFeOx) was found at 150 °C. Meanwhile, the higher relative proportion of irreversible activity loss was found at lower temperatures, which is associated with the more easily saturated chemical adsorption of SO2 as evidenced by SO2+O2 breakthrough test. At higher temperatures, the SO2 oxidation and its further transformation into NH4HSO4 could be favored, thus resulting in increased reversible activity loss. The FeOx modification can protect MnOx species from sulfation to a certain degree and lower the irreversible deactivation, which is evidenced by the binding energy upshift and downshift of Fen+ species after being poisoned and regenerated, as well as the slightly changed binding energy of Mnn+ species from the XPS analysis.

Unveiling the Origin of Selectivity in the Selective Catalytic Reduction of NO with NH3 over Oxide Catalysts.

The trade-off between activity and selectivity is a century-old puzzle in catalysis. In the selective catalytic reduction of NO with NH3 (NH3-SCR), various typical oxide catalysts exhibit distinct characteristics of activity and selectivity: Mn-based catalysts show outstanding low-temperature activity and poor N2 selectivity, mainly caused by N2O formation, while Fe- and V-based catalysts possess inverse characteristics. The underlying mechanism, however, has remained elusive. In this study, by combining experimental measurements and density functional theory calculations, we demonstrate that the distinct difference in the selectivity of oxide catalysts is determined by the gap in the energy barriers between N2 formation and N2O formation from the consumption of the key intermediate NH2NO. The gaps in the energy barriers follow the order of α-MnO2 < α-Fe2O3 < V2O5/TiO2, in correspondence with the order of N2 selectivity of the catalysts. This work discloses the intrinsic link between the target reaction and side reactions in the selective catalytic reduction of NO, providing fundamental insights into the origin of selectivity.

Carbon monoxide+ammonia coupling denitration at low temperatures over manganese–cerium/activated carbon catalysts

To identify the mechanism of the low-temperature CO + NH3 coupling selective catalytic reduction (SCR) denitration process, a series of Mn–Ce/activated carbon catalysts differing in the Ce content were prepared and characterized via SEM, EDS, XRD, XPS, FTIR and evaluated in the CO + NH3 coupling SCR denitration. The results show that the denitrification rates of Mn-Ce/AC catalysts are in the order of 7Mn-3Ce/AC > 7Mn-5Ce/AC > 7Mn-1Ce/AC at a temperature range of 150 °C–300 °C and an oxygen content of 9%. A moderate Ce content provides a smooth catalyst surface with a homogeneous distribution of metal particles and pores, resulting in the optimization of the physical and chemical performance of the Mn-based catalyst. As a result, more active oxygen species and lattice defects are formed, which promoted the dispersion of active components on the catalyst surface, increased the adsorption sites of CO and NH3, and provided more active sites for denitration reaction. Mn4+ and Ce3+ both increased to varying degrees, and oxygen-containing functional groups carboxyl and lactone groups increased, which promoted the synergistic reaction between MnCe, enhancing the NO adsorption and conversion rate. At 150 °C–250 °C, the CO + NH3 coupling denitration is mainly governed by physical adsorption, whereas chemical adsorption is the predominant mechanism at 250 °C–300 °C. The denitration process includes four stages: reaction gas adsorption, adsorption molecular dissociation, catalytic denitration of metal active components and product desorption.

Improved N2 Selectivity of MnOx Catalysts for NOx Reduction by Engineering Bridged Mn3+ Sites

Mn-based catalysts are promising for selective catalytic reduction (SCR) of NOx with NH3 at low temperatures due to their excellent redox capacity. However, the N2 selectivity of Mn-based catalysts is an urgent problem for practical application owing to excessive oxidizability. To solve this issue, we report a Mn-based catalyst using amorphous ZrTiOx as the support (Mn/ZrTi-A) with both excellent low-temperature NOx conversion and N2 selectivity. It is found that the amorphous structure of ZrTiOx modulates the metal-support interaction for anchoring the highly dispersed active MnOx species and constructs a uniquely bridged Mn3+ bonded with the support through oxygen linked to Ti4+ and Zr4+, respectively, which regulates the optimal oxidizability of the MnOx species. As a result, Mn/ZrTi-A is not conducive to the formation of ammonium nitrate that readily decomposes to N2O, thus further increasing N2 selectivity. This work investigates the role of an amorphous support in promoting the N2 selectivity of a manganese-based catalyst and sheds light on the design of efficient low-temperature deNOx catalysts.

Stable and Active Au Catalyst Supported on CeMnO3 Perovskite for Selective Oxidation of Glycerol.

The selective oxidation of glycerol holds promise to transform glycerol into value-added chemicals. However, it remains a big challenge to achieve satisfactory selectivity toward the specific product at high conversion due to the multiple reaction pathways. Here, we prepare a hybrid catalyst via supporting Au nanoparticles on CeMnO3 perovskite with a modest surface area, achieving promoted conversion of glycerol (90.1%) and selectivity of glyceric acid (78.5%), which are much higher than those of CeMnOx solid-solution-supported Au catalysts with larger surface area and other Ce-based or Mn-based Au catalysts. The strong interaction between Au and CeMnO3 perovskite facilitates the electron transfer from the B-site metal (Mn) in the CeMnO3 perovskite to Au and stabilizes Au nanoparticles, which results in the enhanced catalytic activity and stability for glycerol oxidation. Valence band photoemission spectral analysis reveals that the uplifted d-band center of Au/CeMnO3 promotes the adsorption of the glyceraldehyde intermediate on the catalyst surface, which benefits further oxidation of glyceraldehyde into glyceric acid. The flexibility of the perovskite support provides a promising strategy for the rational design of high-performance glycerol oxidation catalysts.

Simultaneous catalytic removal of NO and chlorobenzene over MnCeSmSnOx: Catalytic performance and removal mechanism

Mn-based catalysts have great potential in the synergistic removal of NO and chlorobenzene but exhibit serious chlorine poisoning and low catalytic activity at low temperatures. In this study, the performance of MnCeOx for simultaneous catalytic removal of NO and chlorobenzene at low temperatures was optimized by the modification of Sm and Sn. Results showed that the modification of Sm and Sn afforded a loose overall structure of the catalyst with a large specific surface area. The addition of Sm and Sn effectively increased the concentration of Mn4+, Ce3+, chemisorbed oxygen, and the amount of acid on the catalyst surface. This considerably improved the activity of the catalyst for simultaneous removal of NO and chlorobenzene at low temperatures. The intermediates formed by the MCSS-0.086 catalyst during the low-temperature simultaneous catalytic removal of NO and chlorobenzene were CHCl3, CCl4, C2HCl3, and C2Cl4. The presence of SnO2 promoted the deep oxidation of chlorobenzene and inhibited the chlorine poisoning of the catalyst. Thus, the low-temperature stability of the catalyst was improved. The chlorobenzene-oxidation efficiency and the NO-removal efficiency of MCSS-0.086 were more than 90% and 95%, respectively, within the range of 178 °C-300 °C. The NH3-selective catalytic reduction curve of NO removal over the MnCeSmSnOx catalyst followed the Langmuir–Hinshelwood mechanism at low temperatures. The catalytic degradation of chlorobenzene finally yielded small molecules: CO2, H2O, and HCl.

Boosting Catalytic Combustion of Ethanol by Tuning Morphologies and Exposed Crystal Facets of α-Mn2O3

Three types of α-Mn2O3 catalysts with different well-defined morphologies (cubic, truncated octahedra and octahedra) and exposed crystal facets have been successfully prepared via hydrothermal processes, and evaluated for ethanol total oxidation with low ethanol concentration at low temperatures. The α-Mn2O3-cubic catalyst shows a superior catalytic reaction rate than that of α-Mn2O3-truncated octahedra and α-Mn2O3-octahedra under high space velocity of 192,000 mL/(g·h). Based on the characterization results obtained from XRD, BET, FE-SEM, HR-TEM, FT-IR, H2-TPR, XPS, ethanol-TPD, and CO-TPSR techniques, the observed morphology-dependent reactivity of α-Mn2O3 catalysts can be correlated to the good low-temperature reducibility, abundant surface Mn4+ and adsorbed reactive oxygen species, which was originated from the exposed (001) crystal planes. Through tuning the morphology and exposed (001) crystal facet of α-Mn2O3, a highly active ethanol oxidation catalyst with high selectivity and excellent stability is obtained. The developed approach may be applied broadly to the development of the design principles for high-performance low-cost and environmentally friendly Mn-based oxidation catalysts.

Identifying the promotional mechanism for the activity and SO2 resistance of Ce-doped K-OMS-2 for the low-temperature SCR of NO with NH3

Mn-based catalysts for the low-temperature selective catalytic reduction (SCR) of NOx by NH3 can be strongly deactivated due to the generation of MnSO4 derived from upstream SO2 and H2O. In this study, a catalyst architecture based on a Ce-doped manganese oxide octahedral molecular sieve (Ce-OMS-2) was successfully synthesized to promote NH3-SCR activity and enhance SO2 tolerance at low temperatures. We investigated the role of Ce and its specific octahedral molecular sieve structure on the anti-SO2 poisoning effect of Ce-OMS-2. Maintaining the manganese oxide octahedral molecular sieve structure with polyvalent manganese species and active oxygen species and the charge transfer between Mn and Ce via the Ce-O-Mn bond in the Ce-OMS-2 catalyst are found to be the key factors for the realization of excellent NH3-SCR activity and SO2 tolerance. In-depth in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS) show that the number of Brønsted acid sites in Ce-OMS-2 can also favor SO2 resistance. This study provides new insight into the mechanism for de-NOx activity and SO2 tolerance on Ce-OMS-2 catalyst and is beneficial for the design of anti-SO2 NH3-SCR catalysts.