Hydrothermal Redox Reaction Research Articles

Phase-controlled synthesis of starch-derived Mo2C–MoC/C heterostructure catalyst for electrocatalytic hydrogen evolution reaction

The electronic structure of molybdenum carbide closely resembles that of Pt, making it a promising candidate material for replacing noble metal catalysts. However, the primary challenge is the controlled and eco-friendly synthesis of molybdenum carbide. Herein, we developed a sustainable and controlled method for synthesizing a heterostructure catalyst for the electrocatalytic hydrogen evolution reaction (HER) using starch as the raw material. Through a hydrothermal redox reaction and subsequent temperature-programmed treatment under an inert atmosphere, the hexagonal Mo2C-cubic MoC heterostructure nanoparticles were dispersed on a carbon matrix. Our investigation into the synthesis process extensively covered the growth of MoO2 nanocrystals and hydrochar during the hydrothermal redox reaction, as well as the phase evolution during the subsequent temperature-programmed treatment. Electrochemical assessments demonstrated the catalyst's remarkable efficiency for the hydrogen evolution reaction across both acidic and alkaline media, achieving a current density of 10 mA/cm2 with an overpotential of 139.4 mV in 1 M KOH solution and 160.7 mV in 0.5 M H2SO4 solution. Combining a series of electrochemical characterizations and applying the distribution of relaxation times (DRT) analysis to operando electrochemical impedance spectroscopy (EIS) data, the superior kinetic performance of the Mo2C–MoC/C was demonstrated, outperforming that of single-phase molybdenum carbide. Furthermore, the catalyst has demonstrated remarkable stability even at high current densities in both acidic and alkaline electrolytes, underscoring its potential as a cathode catalyst in both alkaline water electrolyzers and proton exchange membrane (PEM) electrolyzers.

Investigation of Charge-Ordered Barium Iron Fluorides with One-Dimensional Structural Diversity and Complex Magnetic Interactions.

Three mixed-valence barium iron fluorides, Ba7Fe7F34, Ba2Fe2F9, and BaFe2F7, were prepared through hydrothermal redox reactions. The characteristic structures of these compounds feature diverse distributions of FeIIF6 octahedra and FeIIIF6 groups. Ba7Fe7F34 contained one-dimensional infinite ∞[FeIIFeIII6F34]14- double chains, comprising cis corner-sharing octahedra along the b direction; Ba2Fe2F9 contained one-dimensional ∞[Fe2F9]4- double chains, consisting of cis corner-sharing octahedra along the chain (a-axis direction) and trans corner-sharing octahedra vertical to the chain, while BaFe2F7 revealed three-dimensional (3D) frameworks that consist of isolated edge-sharing dinuclear FeII2F10 units linked via corners by FeIIIF6 octahedra. Magnetization and Mössbauer spectroscopy measurements revealed that Ba7Fe7F34 exhibits an antiferromagnetic phase transition at ∼11 K, where ferrimagnetic ∞[FeIIFeIII6F34]14- double chains are arranged in a paralleling manner, while Ba2Fe2F9 shows canted antiferromagnetic ordering at ∼32.5 K, leading to noncollinear spin ordering.

Syntheses, structures, and magnetism of new vanadium and iron fluoride phosphates Ax(NH4)3-xM4(PO4)2F7(OH)2 (A=K, Rb, Cs, and M= V, Fe) containing novel structural motifs

Five new vanadium and iron fluoride phosphates Ax(NH4)3-xM4(PO4)2F7(OH)2 (A = K, Rb, Cs, and M = V, Fe) were prepared through hydrothermal redox reactions. All compounds crystallize in the monoclinic crystal system, space group P21/m. The crystal structure constitutes three-dimensional frameworks with channels extending along [001] where A+ or (NH4)+ ions reside in the channels. Novel structural motifs are made up of ∞[M4O8F7(OH)2]10− chains formed by corner-shared cubane M4 clusters. In the isostructural series, the interconnection between these units feature corner-shared cubane M4 S = 1 spin-chains (M = V3+) and corner-shared cubane M4 S = 5/2 spin-chain (M = Fe3+), which all promote antiferromagnetic (AFM) interactions.

High-Valence-Manganese Driven Strong Anchoring of Iridium Species for Robust Acidic Water Oxidation.

Designing an efficient and durable electrocatalyst for the sluggish anodic oxygen evolution reaction (OER) has been the primary goal of using proton exchange membrane electrolyzer owing to the highly acidic and oxidative environment at the anode. In this work, it is reported that high-valence manganese drives the strong anchoring of the Ir species on the manganese dioxide (MnO2 ) matrix via the formation of an Mn-O-Ir coordination structure through a hydrothermal-redox reaction. The iridium (Ir)-atom-array array is firmly anchored on the Mn-O-Ir coordination structure, endowing the catalyst with excellent OER activity and stability in an acidic environment. Ir-MnO2 (160)-CC shows an ultralow overpotential of 181mV at j = 10mA cm-2 and maintains long-term stability of 180h in acidic media with negligible decay, superior to most reported electrocatalysts. In contrast, when reacting with low-valence MnO2 , Ir species tend to aggregate into IrOx nanoparticles, leading to poor OER stability. Density functional theory (DFT) calculations further reveal that the formation of the Mn-O-Ir coordination structure can optimize the adsorption strength of *OOH intermediates, thus boosting the acidic OER activity and stability.

One-pot synthesis of Ru/Nb2O5@Nb2C ternary photocatalysts for water splitting by harnessing hydrothermal redox reactions

MXenes, 2D transition metal carbides/nitrides, have been demonstrated as promising platform for fabricating novel composites with interesting photo-/electrochemical properties. It is desirable to gain insights into the reactivity of MXenes, enabling the controllable transformation of MXenes. Here, a one-pot hydrothermal synthesis method of MXene-based photocatalyst is validated by harnessing the reducibility of Nb2CTx MXene. The origin of reducibility of Nb2CTx during the hydrothermal oxidation process was demonstrated as the active hydrogen produced from the water splitting in the presence of Nb2CTx, which reduced Ru3+ in situ to Ru nanoparticles on Nb2O5 nanowires derived from Nb2CTx. Compared with the traditional photo-deposition method, the chemical valance of the noble metal Ru/Pt obtained by the one-pot synthesis method was closer to the metal state, which reduced the charge transfer resistance by 82.5%. It led to the photocatalytic hydrogen production of 10.11 mmol·h−1·g−1 with 41.25% apparent quantum yield at 313 nm.

Variable Structures and One-Dimensional-Canting Antiferromagetism Found in Fluoride Selenates, A2Mn(SeO4)F3 (A = K, Rb, Cs).

Three new alkali-metal manganese fluoride selenates, A2Mn(SeO4)F3 (A = K, Rb, Cs), were prepared through hydrothermal redox reactions. The products consisted of one-dimensional polymeric anionic ∞[Mn(SeO4)F3]2- chains, where the A+ cations are connected by O and/or F atoms to form blocks with two-dimensional layers. A2Mn(SeO4)F3 (A= Rb, Cs) is isostructural with the monoclinic space group P21/c, while K2Mn(SeO4)F3 crystallizes in the orthorhombic space group Pbcn. A2Mn(SeO4)F3 (A = K, Rb, Cs) forms spin chains of Mn3+ with different Mn-F-Mn bridges, which showed canting antiferromagnetic behaviors. Single-crystal magnetic measurements revealed that the magnetic moments of the Mn ions were more canted for larger alkali-metal compounds in an antiferromagnetically ordered state.

Nanotubular OMS-2 Supported Single-Atom Platinum Catalysts Highly Active for Benzene Oxidation

The cryptomelane-type octahedral molecular sieve (OMS-2) exhibits excellent catalytic activity for the oxidation of volatile organic compounds (VOCs) due to its unique structure, and single-atom catalysts (SACs) have recently attracted much attention in heterogeneous catalysis. Herein, we adopted the hydrothermal redox reaction of KMnO4 and HCl aqueous solution at 120 °C for 12 h to first synthesize the nanotubular OMS-2 support and used the vitamin C and NaBH4 reduction methods to prepare the OMS-2-supported single-atom Pt and PtNP catalysts for benzene oxidation, respectively. It was found that the OMS-2-supported single-atom Pt catalyst with a Pt loading of 0.0383 wt % (0.0383Pt1/OMS-2) exhibited the best catalytic performance for benzene oxidation (a 90% benzene conversion was achieved at 189 °C and 20 000 mL g–1 h–1 (space velocity)), which was associated with its high surface oxygen vacancy density, good low-temperature reducibility, and strong benzene adsorption ability. It was also shown that benzene could be dissociated more readily over the supported single-atom Pt1 catalyst than over the supported PtNP catalyst, and the phenolates or benzoquinone as well as methyl groups, lipid, and vinyl species were the main intermediates in the oxidation of benzene over 0.0383Pt1/OMS-2. The results of this study are useful in developing the high-performance single-atom catalysts that can be applied for the oxidative removal of VOCs.

A highly effective urchin-like MnCrOx catalyst for the selective catalytic reduction of NOx with NH3

A novel urchin-like catalyst (MnCrOx-UL) was successfully synthesized by hydrothermal redox reaction. In addition, a reference sample (MnCrOx) was prepared by co-precipitation process for comparison. Experimental results revealed that MnCrOx-UL showed superior NH3-SCR performance in the temperature range of 150–350 °C and high resistance to SO2. The results of characterization demonstrated that MnCrOx-UL showed larger surface area, more acidic sites, higher redox capacity and more oxygen vacancies compared with MnCrOx. Additionally, more activated adsorbed species over MnCrOx-UL sample surface could also effectively improve the NH3-SCR performance at low temperature.

Vanadium-doped MnO2 for efficient room-temperature catalytic decomposition of ozone in air

Outdoor or indoor ozone pollution recently regains the attentions due to new findings on its risk even at very low level. The room-temperature catalytic material is key to abate indoor ozone pollution. Here we prepared a series of vanadium-doped MnO2 (V-MnO2) via a one-step hydrothermal redox reaction between MnO4− and Mn2+ with addition of vanadate. The vanadium-doped MnO2 exhibited weaker crystallinity with exposure of high-index facets such as (301), much larger specific surface area, enhanced surface acidity and had lower oxidation state of Mn. Accordingly, the amount of oxygen vacancies was greatly increased, which is not only revealed by H2-TPR and O2-TPD but also confirmed by stronger peroxide signals in electron paramagnetic resonance. V-MnO2(0.15) with the largest specific surface area of 309.8 m2/g not only exhibited stable activity for high concentration of ozone under humid condition, it also showed high ozone removal efficiency when it was coated on the low pressure-drop nonwoven fabric under the real filtration velocity. Thus, vanadium-doping is a facile method to improve the room-temperature activity of MnO2 for indoor ozone decomposition under the humid condition.

Hydrothermal Production of H2 and Magnetite From Steel Slags: A Geo-Inspired Approach Based on Olivine Serpentinization

The interaction between ultramafic rocks and hot seawater at slow-spreading mid-oceanic ridges triggers hydrothermal redox reactions which are known to produce magnetite and H2 under appropriate pressure and temperature conditions. Steel slags share some common properties with ultramafic rocks. They are composed of anhydrous and refractory minerals formed at temperatures exceeding 1200°C and they contain ferrous iron in comparable amounts. Consequently, both types of materials, natural and anthropogenic, when submitted to hydrothermal conditions are prone to form magnetite and H2 according the simplified redox reaction: 3[FeO] + H2O => Fe3O4 + H2 (1) where [FeO] is the ferrous iron component of the corresponding material that can be present under different mineralogical forms. Since H2 and magnetite, Fe3O4, especially when occurring as nanomaterial, are two valuable products for new-technology applications, the hydrothermal treatment of steel slags can be seen as a way to valorize a by-product of the steel industry of which a few tenths of billion tons are produced yearly. The hydrothermal behavior of steel slags which arise from basic oxygen furnace (BOF) operations and that of olivine, (Mg,Fe)2SiO4, the main mineral constituent of abyssal peridotites, is described here based on literature data. The thermochemical characteristics of Reaction 1 are reviewed for both types of materials in the perspective of optimizing a process that would valorize BOF steel slags for the production of nanomagnetite (and high-purity H2). In particular the kinetics effect of temperature, pH and solution-to-solid mass ratio on the hydrothermal oxidation of wustite (FeO), considered here as an analogue of ferrous-iron component of steel slags, is modeled. The possible role of additive (impurity) on the hydrothermal oxidation of wustite though the catalysis of the water-splitting reaction is discussed. Finally, the lack of kinetics constraints on nanomagnetite growth under hydrothermal conditions in a wide range of pH is identified has a major gap to understand two important issues, (1) the catalysis of abiotic molecules in the course of serpentinization reactions and (2) tailoring the size of the magnetite produced by hydrothermal treatment of BOF steel slags.

Formation of CeMnxOy/OMS-2 nanocomposite significantly enhances UV–vis-infrared light-driven catalytic activity

The CeMnxOy/OMS-2 nanocomposites were prepared by depositing different amounts of amorphous CeMnxOy on the pure OMS-2 sample by the hydrothermal redox reaction of Ce(NO3)3 and KMnO4. The formation of the CeMnxOy/OMS-2 nanocomposites causes a significant enhancement in the photothermocatalytic activity of OMS-2 for the gas-phase oxidation of benzene under the UV–vis-infrared illumination from a Xe lamp. The optimum CeMnxOy/OMS-2-5.0% nanocomposite exhibits very effective photothermocatalytic activity and very good durability under the UV–vis-infrared illumination. It also exhibits effective photothermocatalytic activity under the visible-infrared and infrared illumination. The significantly enhanced photothermocatalytic activity of the CeMnxOy/OMS-2-5.0% nanocomposite as compared to the pure OMS-2 sample is attributed to the much higher thermocatalytic activity of the former than the latter due to a significant improvement in the reducibility upon the formation of the CeMnxOy/OMS-2-5.0% nanocomposite. A novel photoactivation quite unlike the photocatalysis on the semiconductor photocatalyst such as anatase TiO2 is found to obviously promote the solar-light-driven thermocatalytic activity.

Sn-Isotope Fractionation as a Record of Hydrothermal Redox Reactions

This work is supported by the National Key R&D Program of China (2016YFC0600405), the GIGCAS No.IS-2547, the National Natural Science Foundation of China (nos. 41672079 and 41372085), and Strategic Priority Research Program (B) of the Chinese Academy of Sciences (XDB1803206).

UV–vis-infrared light-driven photothermocatalytic abatement of CO on Cu doped ramsdellite MnO2 nanosheets enhanced by a photoactivation effect

The Cu doped ramsdellite MnO2 nanosheet samples with different Cu/Mn molar ratio were prepared by a facile hydrothermal redox reaction among Cu(NO3)2, Mn(NO3)2, and KMnO4 at 60°C. They were characterized by ICP-OES, XRD, TEM, SEM, N2 adsorption, XPS, UV-vis-IR absorption, etc. The Cu doped ramsdellite MnO2 nanosheet samples demonstrate highly efficient photothermocatalytic activity and very good catalytic stability for the catalytic purification of CO as one of poisonous air pollutants under the full solar spectrum infrared irradiation. Compared to the pure ramsdellite MnO2 nanosheet sample and TiO2(P25), the photothermocatalytic activity of the optimum Cu doped ramsdellite MnO2 nanosheet sample under the full solar spectrum irradiation is enhanced by 2.3, 281.7 times, respectively. The Cu doped ramsdellite MnO2 nanosheet sample also demonstrates highly efficient catalytic activity even under the λ>830nm infrared irradiation. The highly efficient catalytic activity of the Cu doped ramsdellite MnO2 nanosheet sample derives from efficient solar-light-driven thermocatalysis because of its strong absorption across the entire full solar spectrum and high thermocatalytic activity. The Cu doping considerably enhances the lattice oxygen activity of ramsdellite MnO2, thus promoting its thermocatalytic activity. A novel photoactivation, completely unlike the well-known photocatalysis on photocatalytic semiconductors such as TiO2, is discovered to further enhance the solar-light-driven thermocatalytic activity. We combine the experimental evidence of CO-TPR and DFT calculation to reveal the origin of the novel photoactivation: the irradiation considerably enhances the lattice oxygen activity of the Cu doped ramsdellite MnO2 nanosheets, thus accelerating their solar-light-driven thermocatalytic activity.

Facile and green fabrication of magnetically recyclable carboxyl-functionalized attapulgite/carbon nanocomposites derived from spent bleaching earth for wastewater treatment

A facile and green hydrothermal approach was employed to fabricate the magnetic carboxyl-functionalized attapulgite/carbon nanocomposites based on the spent bleaching earth. The preparation process simultaneously involved the growth of magnetic nanoparticles and the coating of carbon species with carboxyl groups on the surface of attapulgite via hydrothermal redox reactions between Fe(III) and sodium citrate in the aqueous solution. The composition, magnetic response as well as adsorption properties of as-prepared nanocomposites could be facilely controlled by adjusting the concentration of sodium citrate. The resultant adsorbents possessed fast adsorption kinetics and the maximum adsorption capacity toward MB and Pb(II) could reach 254.83mg/g and 312.73mg/g while the concentration of sodium citrate was 0.6M. In addition, the adsorbent could be easily recycled due to its magnetism and the adsorption capacity had a slight decrease after six adsorption-desorption cycles. All the information revealed that the carboxyl-functionalized attapulgite/carbon nanocomposites were expected to be a promising candidate for high-efficient removal of contaminants from wastewater in future practical use.

Efficient UV–vis-infrared light-driven catalytic abatement of benzene on amorphous manganese oxide supported on anatase TiO2 nanosheet with dominant {001} facets promoted by a photothermocatalytic synergetic effect

The nanocomposites of amorphous manganese oxide (MnOx) supported on anatase TiO2 nanosheet with dominant {001} facets (TNS) with different Mn/Ti molar ratio were prepared by hydrothermal redox reaction of KMnO4 and Mn(NO3)2 in the presence of TNS. The MnOx/TNS nanocomposites were characterized by XRD, SEM, TEM, ICP, XPS, BET, and diffuse reflectance UV–vis-Infrared adsorption. MnOx/TNS with the optimum Mn/Ti molar ratio of 0.40 exhibits highly efficient photothermocatalytic activity and excellent durability for the oxidation of the recalcitrant and carcinogenic benzene under the full solar spectrum irradiation from a Xe lamp. Remarkably, the CO2 production rate of MnOx/TNS enhances by 99 times as compared to TNS. Impressively, MnOx/TNS also exhibits efficient photocatalytic activity with the visible-infrared irradiation, even with the infrared irradiation. The highly efficient photothermocatalytic activity of MnOx/TNS under the full solar spectrum irradiation originates from the highly efficient solar light-driven thermocatalysis on MnOx due to its strong absorption in entire solar spectrum region and the efficient thermocatalytic activity, which is considerably promoted by a photothermocatalytic synergetic effect. We put insight into the photothermocatalytic synergetic effect by CO temperature-programmed reduction of MnOx/TNS in dark and with the solar light irradiation: the active species generated by the photocatalysis on TNS migrate to MnOx via the MnOx/TiO2 interface, and accelerate the solar light-driven thermocatalysis on MnOx in the nanocomposite.

Cu doped OL-1 nanoflower: A UV–vis-infrared light-driven catalyst for gas-phase environmental purification with very high efficiency

The nanoflowers of Cu doped octahedral layered birnessite (Cu-OL-1) were prepared by a facile method of hydrothermal redox reaction between Cu(NO3)2, Mn(NO3)2, and KMnO4. The Cu-OL-1 samples were characterized by XRD, TEM, SEM, ICP, BET, etc. Remarkably, the Cu-OL-1 exhibits very high catalytic activity for the abatement of air pollutants (e.g. CO and benzene) with the irradiation of full solar spectrum, visible-infrared, or infrared light. The high catalytic activity of Cu-OL-1 originates from the efficient solar light-driven thermocatalysis, which is attributed to its high thermocatalytic activity and strong absorption in the whole solar spectrum region. The Cu doping in OL-1 significantly enhances its thermocatalytic activity due to a considerable enhancement in the activity of lattice oxygen in OL-1. A conceptually novel photoactivation different from the conventional photoactivation on semiconductors (e.g. TiO2) is found to enhance the activity of lattice oxygen in OL-1, thus accelerating the thermocatalysis on Cu-OL-1. We reveal the origin of the novel photoactivation by CO temperature-programmed reduction in dark and with solar light irradiation, and density functional theory (DFT) calculations.

Synthesis of Few-Layer MoS2 Nanosheets-Wrapped Polyaniline Hierarchical Nanostructures for Enhanced Electrochemical Capacitance Performance

We report a facile strategy to synthesize a hierarchical core-sheath PANi@MoS2 nanocomposite as an advanced electrode material for high-performance electrochemical capacitor applications. Hierarchical core-sheath PANi@MoS2 nanostructure is prepared in a one-pot synthesis via a hydrothermal redox reaction between ammonium tetrathiomolybdate and polyaniline nanofibers. Structural and morphological characterizations of the as-prepared PANi@MoS2 nanocomposite are investigated by Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectrum (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements. The obtained PANi@MoS2 electrode displays a good electrochemical capacitance performance with a specific capacitance of 450Fg−1 under 0.5M H2SO4. More importantly, the core-sheath structure of PANi@MoS2 electrode enhances the structural stability during the electrochemical process and thus improves the electrochemical cycling stability of the electrode significantly, which retains 80% in specific capacitance after 2000 charge/discharge processes.

Remarkable promotion effect of trace sulfation on OMS-2 nanorod catalysts for the catalytic combustion of ethanol

OMS-2 nanorod catalysts were synthesized by a hydrothermal redox reaction method using MnSO4 (OMS-2-SO4) and Mn(CH3COO)2 (OMS-2-AC) as precursors. SO42−-doped OMS-2-AC catalysts with different SO42− concentrations were prepared next by adding (NH4)2SO4 solution into OMS-2-AC samples to investigate the effect of the anion SO42− on the OMS-2-AC catalyst. All catalysts were then tested for the catalytic oxidation of ethanol. The OMS-2-SO4 catalyst synthesized demonstrated much better activity than OMS-2-AC. The SO42− doping greatly influenced the activity of the OMS-2-AC catalyst, with a dramatic promotion of activity for suitable concentration of SO42− (SO4/catalyst=0.5% W/W). The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma optical emission spectroscopy (ICP-OES), NH3-TPD and H2-TPR techniques. The results showed that the presence of a suitable amount of SO42− species in the OMS-2-AC catalyst could decrease the Mn–O bond strength and also enhance the lattice oxygen and acid site concentrations, which then effectively promoted the catalytic activity of OMS-2-AC toward ethanol oxidation. Thus it was confirmed that the better catalytic performance of OMS-2-SO4 compared to OMS-2-AC is due to the presence of some residual SO42− species in OMS-2-SO4 samples.

Hydrothermal synthesis and characterization of surface-modified δ-MnO2 with high Fenton-like catalytic activity

Surface-modified δ-MnO2 with a hierarchical structure was synthesized via a hydrothermal redox reaction between toluene and KMnO4. Toluene is oxidized to produce benzoic acid which rapidly adsorbs onto the surface of δ-MnO2. The δ-MnO2 sample prepared with toluene exhibited a much higher catalytic activity for the Fenton-like oxidation of methylene blue in aqueous solution than that prepared without toluene. The enhanced catalytic activity might be attributed to the surface-bound persistent free radicals produced from the electron transfer from the adsorbed C6H5–COO− to Mn(IV).

The effect of Ce ion substituted OMS-2 nanostructure in catalytic activity for benzene oxidation.

The nanostructure of Ce doped OMS-2 plays a very important role in its catalytic property. We demonstrate by density functional theory (DFT) calculations that the unique nanostructure of the Ce ion substituted OMS-2 with Mn vacancy in the framework is beneficial for the improvement of catalytic activity, while the nanostructure of the Ce ion substituted OMS-2 without defects are detrimental to the catalytic activity. We establish a novel and facile strategy of synthesizing these unique Ce ion substituted OMS-2 nanostructure with Mn vacancies in the framework by hydrothermal redox reaction between Ce(NO3)3 and KMnO4 with KMnO4/Ce(NO3)3 at a molar ratio of 3 : 1 at 120 °C. Compared to pure OMS-2, the produced catalyst of Ce ion substituted OMS-2 ultrathin nanorods exhibits an enormous enhancement in the catalytic activity for benzene oxidation, which is evidenced by a significant decrease (ΔT(50) = 100 °C, ΔT(90) = 129 °C) in the reaction temperature of T50 and T90 (corresponding to the benzene conversion = 50% and 90%), which is considerably more efficient than the expensive supported noble metal catalyst (Pt/Al2O3). We combine both theoretical and experimental evidence to provide a new physical insight into the significant effect due to the defects induced by the Ce ion substitution on the catalytic activity of OMS-2. The formation of unique Ce ion substituted OMS-2 nanostructure with Mn vacancies in the framework leads to a significant enhancement of the lattice oxygen activity, thus tremendously increasing the catalytic activity.