Metal-support Interaction Effect Research Articles

Enhancing activity and durability of Pd nanoparticle electrocatalyst by ceria undercoating on carbon support

Pd/C catalysts consisted of Pd nanoparticles (NPs) on carbon support are an important electrocatalyst in fuel cells operating on small molecules such as formic acid, methanol, and ethanol. Enhancing the performance and durability of Pd/C catalyst is an urgent issue for the commercialization of such fuel cells. Towards these ends, in this work, we report a facile sonochemical method to form a novel Pd/CeO2/C catalyst with a CeO2 undercoating layer between Pd NPs and carbon support. The CeO2 undercoating layer is composed of ~6 nm sized CeO2−x (x ~ 0.17) NPs densely covering the carbon surface. The Pd NPs in Pd/CeO2/C catalyst are formed on top of the CeO2 NPs. Spectroscopic and electrochemical analysis data indicate the presence of strong metal-support interaction (SMSI) effect between Pd and CeO2. Formic acid oxidation reaction (FAOR), studied as an exemplary reaction of electrocatalysis on Pd/CeO2/C catalyst, is enhanced from that of Pd/C catalyst by 2.4 times for specific activity and 4.8 times for mass activity. Pd/CeO2/C catalyst shows ~70% of retention of mass activity after 1000 cycles of FAO reaction, much higher than ~29% of Pd/C.

Metal-support interaction enhanced electrochemical reduction of CO2 to formate between graphene and Bi nanoparticles

Metal nanoparticles stabilized on a support material have been explored extensively to boost heterogeneous catalysis. Herein, the effect of metal-support interaction between bismuth (Bi) nanoparticles and reduced graphene oxide nanosheets (Gr) on the electroreduction of CO2 towards value-added formate is explored. The obtained Bi/Gr hybrid catalysts exhibit a superior catalytic activity towards electrochemical reduction of CO2, which gives the maximum faradic efficiency of 92.1 % at -0.97 V (vs. RHE) for formate generation. Particularly, the hydride shows an enhancement to the catalysts of bare Bi and physical mixture of Bi and Gr, with a high current density of 28.1 mA∙cm−2 and production rate of 0.53 mol∙cm−2 h-1 at -1.17 V (vs. RHE) for formate generation. The electrochemical analysis reveals that the metal-support interactions substantially boost CO2 electroreduction activity through modification the electronic structure and improving interfacial electron transfer between Bi and Gr. This work not only deepens an understanding of metal-support interaction effect but also sheds light on the design of high-efficiency catalysts toward CO2 electroreduction by virtue of the interactions between active metals and carbon-like support.

Promotion effect of strong metal-support interaction to thermocatalytic, photocatalytic, and photothermocatalytic oxidation of toluene on Pt/SrTiO3

The importance of strong metal-support interaction (SMSI) in reducible oxide supported noble metal nanoparticles (NP) has been recognized in many thermocatalytic systems but rarely explored in photocatalytic and photothermocatalytic systems. Herein, the promotion effect of SMSI in strontium titanate (STO) supported Pt NP for thermocatalytic, photocatalytic, and photothermocatalytic oxidation (TCO, PCO and PTO) of toluene is reported. SMSI in Pt/STO is achieved through calcination in air (Air-Pt/STO), reduction in H2 atmosphere (H2–Pt/STO), wet reduction in HCHO solution (HCHO–Pt/STO) or NaBH4 solutions (NaBH4–Pt/STO), resulting in the formation of chemisorbed oxygen and negatively charged Pt NP and promoting oxygen activation in TCO and surface plasmon resonance effects of Pt NP in visible-light-induced PCO and PTO. Both TCO and PCO activities go along with the degree of SMSI as Air-Pt/STO > H2–Pt/STO > HCHO–Pt/STO > NaBH4–Pt/STO. Under both visible-light illuminating and thermal environment at 150 °C, the PTO toluene degradation efficiency of Air-Pt/STO is further improved with a factor of 32 times or 9 times than the single PCO or TCO process. The unique synergistic photothermocatalytic oxidation performance of Air-Pt/STO is ascribed to the function of Pt NP and the effect of SMSI. Our findings provide a facile way to design multifunctional supported noble metal catalysts for efficient VOCs degradation process.

Anchoring IrPdAu Nanoparticles on NH2-SBA-15 for Fast Hydrogen Production from Formic Acid at Room Temperature.

Hydrogen (H2), a regenerable and promising energy carrier, acts as an essential role in the construction of a sustainable energy system. Formic acid (HCOOH, FA), a natural biological metabolic products and also accessible through carbon dioxide (CO2) reduction, has a great potential to serve as a prospective H2 supplier for the fuel cell. Herein, ultrafine and electron-rich IrPdAu alloy nanoparticles with a size of 1.4 nm are highly dispersed on amine-modified mesoporous SiO2 (NH2-SBA-15) and used as a highly active and selective catalyst for fast H2 production from FA. The as-synthesized IrPdAu/NH2-SBA-15 possesses superior catalytic activity and 100% H2 selectivity with initial turnover frequency values of 6316 h-1 with the additive of sodium formate (SF) and 4737 h-1 even without SF at 298 K, comparable to the most effective heterogeneous catalysts ever published. The excellent performance of IrPdAu/NH2-SBA-15 was not only ascribed to the combination of the electronic synergistic effect of trimetallic alloys and the strong metal-support interaction effect but also attributed to the amine (-NH2) alkaline groups grafted on SBA-15, which is beneficial to boost the split of the O-H bond of FA.

Sea-Island-Like Morphology of CuNi Bimetallic Nanoparticles Uniformly Anchored on Single Layer Graphene Oxide as a Highly Efficient and Noble-Metal-Free Catalyst for Cyanation of Aryl Halides

Aryl nitriles are versatile compounds that can be synthesized via transition-metal-mediated cyanation of aryl halides. Most of the supported-heterogeneous catalysts are noble-metals based and there are very limited numbers of efficient non-noble metal based catalysts demonstrated for the cyanation of aryl halides. Herein, bimetallic CuNi-oxide nanoparticles supported graphene oxide nanocatalyst (CuNi/GO-I and CuNi/GO-II) has been demonstrated as highly efficient system for the cyanation of aryl halides with K4[Fe(CN)6] as a cyanating agent. Metal-support interaction, defect ratio and synergistic effect with the bimetallic nanocatalyst were investigated. To our delight, the CuNi/GO-I system activity transformed a wide range of substrates such as aryl iodides, aryl bromides, aryl chlorides and heteroaryl compounds (Yields: 95–71%, TON/TOF: 50–38/2 h−1). Moreover, enhanced catalytic performance of CuNi/GO-I and CuNi/GO-II in reduction of 4-nitropehnol with NaBH4 was also confirmed (kapp = 18.2 × 10−3 s−1 with 0.1 mg of CuNi/GO-I). Possible mechanism has been proposed for the CuNi/GO-I catalyzed cyanation and reduction reactions. Reusability, heterogeneity and stability of the CuNi/GO-I are also found to be good.

Effect of spinel inversion and metal-support interaction on the site activity of Mg-Al-Ox supported Co catalyst for CO2 reforming of CH4

The active metal–support interaction, as well as spinel inversion was studied for site formation, properties, activity and site resistance to carbon deposition in dry reforming of methane (DRM) using Al-Ox and Mg-Al-Ox supported Ni and Co monometallic catalysts. A change in support from Al-Ox to Mg-Al-Ox led to transformation of hysteresis loop from H2 to H4 as revealed by the N2 adsorption results, while additional MgO phase was observed from the XRD results of the catalysts. Phase quantification of the XRD showed a reduction from 100% to 45% spinel with the introduction of Mg in the support. Al and Mg K-edge XANES results revealed changes in the co-ordination number (CN) of Mg and Al inside the support, leading to spinel inversion, which ultimately affected the distribution of Ni and Co, as well as site formation on the support system. STEM EDX revealed different interaction/distribution of active metals on the support system. Co showed a uniform distribution, while Ni showed a heterogeneous distribution in addition to the isolated NiO formed on the surface of the support. The K-edge XANES results showed that more Ni sites were generated than Co sites during reduction, but Co sites showed better conversion rate for CO2, CH4, in DRM, and resistance to deactivation, which was also confirmed by the calculated TOF. This improved performance of Co sites was attributed to the better basicity per active site generated from its interaction with MgO (from the support) as compared to the Ni sites.

Well-Defined Materials for Heterogeneous Catalysis: From Nanoparticles to Isolated Single-Atom Sites.

The use of well-defined materials in heterogeneous catalysis will open up numerous new opportunities for the development of advanced catalysts to address the global challenges in energy and the environment. This review surveys the roles of nanoparticles and isolated single atom sites in catalytic reactions. In the second section, the effects of size, shape, and metal-support interactions are discussed for nanostructured catalysts. Case studies are summarized to illustrate the dynamics of structure evolution of well-defined nanoparticles under certain reaction conditions. In the third section, we review the syntheses and catalytic applications of isolated single atomic sites anchored on different types of supports. In the final part, we conclude by highlighting the challenges and opportunities of well-defined materials for catalyst development and gaining a fundamental understanding of their active sites.

Engineering stable Pt nanoparticles and oxygen vacancies on defective TiO2 via introducing strong electronic metal-support interaction for efficient CO2 photoreduction

This work for the first time reports the promoting effect of strong electronic metal-support interaction (EMSI) in Pt/TiO2-VO (VO: oxygen vacancy) for gas-phase CO2 photoreduction. A novel in-situ surface hydrogenation was developed to prepare hydrogenated Pt/TiO2-VO in a continuous, high throughput diffusion flame aerosol reactor. The combined results of various characterization techniques confirmed the presence of EMSI between Pt and defective TiO2-VO resulted in the enhanced electronic density of Pt nanoparticles. Both the modulated electronic structure of Pt and surface oxygen vacancies simultaneously promoted the activation of surface adsorbed carbon intermediates and facilitated the separation of photogenerated charges, eventually boosting the photocatalytic activity of Pt/TiO2-VO. The optimized Pt/TiO2-VO demonstrated a high quantum yield of 1.49% with high CH4 selectivity (81%), which rendered 5.8- and 1.2-fold enhancements over its counterparts of TiO2-VO and Pt/TiO2. More significantly, the EMSI also played a critical role in preserving the surface metallic Pt0 and oxygen vacancies, and in sustaining high activity of the Pt/TiO2-VO, whereas rapid catalytic deactivation are observed for both TiO2-VO and Pt/TiO2.

Effect of Surface Composition and Structure of the Mesoporous Ni/KIT-6 Catalyst on Catalytic Hydrodeoxygenation Performance

A series of Ni/KIT6 catalyst precursors with 25 wt.% Ni loading amount were reduced in H2 at 400, 450, 500, and 550 °C, respectively. The studied catalysts were investigated by XRD, Quasi in-situ XPS, BET, TEM, and H2-TPD/Ranalysis methods. It was found that reduction temperature is an important factor affecting the hydrodeoxygenation (HDO) performance of the studied catalysts because of the Strong Metal Support Interaction Effect (SMSI). The reduction temperature influences mainly the content of active components, crystal size, and the abilityfor adsorbing and activating H2. The developed pore structure and large specific surface area of the KIT-6 support favored the Ni dispersion. The RT450 catalyst, which was prepared in H2 atmosphere at 450 °C, has the best HDO performance. Ethyl acetate can be completely transformed and maintain 96.8% ethane selectivity and 3.2% methane selectivity at 300 °C. The calculated apparent activation energies of the prepared catalysts increased in the following order: RT550 > RT400 > RT500 > RT450.

Kinetic Modelling of Co3O4- and Pd/Co3O4-Catalyzed Wet Lean Methane Combustion

Reaction kinetics of methane combustion is investigated on Co3O4 and Pd/Co3O4 (0.27 wt% Pd) catalysts for a fuel-lean feed. The temperature ranges between 250 and 550 °C in the presence of 5 and 10 vol% water with CH4 concentrations that varied between 1000 and 5000 ppmv. Significant cobalt oxide contribution to the activity of the bimetallic catalyst is observed, especially at higher water concentration and lower temperature (up to 70%). Co3O4 demonstrates first order to CH4, 0 order to H2O and activation energy of 69 kJ/mol. Pd/Co3O4 catalyst shows first order to CH4, negative 0.37 order to H2O and an observed activation energy of 90.7 kJ/mol, which is corrected for water adsorption to 60.6 kJ/mol. The latter is a typical activation energy for Pd/Al2O3 catalyst at similar conditions, indicating that the Co3O4 contribution is not only in performing the methane combustion itself but also in supplying surface oxygen rather than in affecting the activation energy. The kinetic evidence shows that the observed behaviour of Pd/Co3O4 catalyst is not a summation of individual activities of Co3O4 and Pd, but rather the effect of strong metal-support interactions (SMSI).

A Theory/Experience Description of Support Effects in Carbon-Supported Catalysts.

The support plays an important role for supported metal catalysts by positioning itself as a macromolecular ligand, which conditions the nature of the active site and contributes indirectly but also sometimes directly to the reactivity. Metal species such as nanoparticles, clusters, or single atoms can be deposited on carbon materials for various catalytic reactions. All the carbon materials used as catalyst support constitute a large family of compounds that can vary both at textural and at structural levels. Today, the recent developments of well-controlled synthesis methodologies, advanced characterization techniques, and modeling tools allow one to correlate the relationships between metal/support/reactant at the molecular level. Based on these considerations, in this Review article, we wish to provide some answers to the question "How and why anchoring metal nanoparticles, clusters, or single atoms on carbon materials for catalysis?". To do this, we will rely on both experimental and theoretical studies. We will first analyze what sites are available on the surface of a carbon support for the anchoring of the active phase. Then, we will describe some important effects in catalysis inherent to the presence of a carbon-type support (metal-support interaction, confinement, spillover, and surface functional group effects). These effects will be commented on by putting into perspective catalytic results obtained in numerous reactions of thermal catalysis, electrocatalysis, or photocatalysis.

Cobalt‐Based Catalyst Supported on Different Morphologies of Alumina for Non‐oxidative Propane Dehydrogenation: Effect of Metal Support Interaction and Lewis Acidic Sites

AbstractDeveloping an economically viable and eco‐friendly catalyst is essential for the dehydrogenation reaction. In this context, cobalt‐based catalysts supported on different morphologies of γ‐Al2O3, nano‐sheet (Al2O3−NS), nano‐fiber (Al2O3−NF) and nano‐plate (Al2O3−NP) were synthesized using wetness impregnation method and tested for non‐oxidative propane dehydrogenation reaction. Metal support interaction and Lewis acidic center play a crucial role in propane dehydrogenation reaction; therefore this study focuses on investigating the role of these parameters on the catalytic activity for cobalt‐based catalysts. A higher metal support interaction was observed in Co/Al2O3−NS as compared to Co/Al2O3−NF and Co/Al2O3−NP. The presence of tetrahedral coordinated Co+2 in Co/Al2O3−NS leads to higher selectivity towards propylene. The formation of metallic cobalt from Co3O4 precursor present in Co/Al2O3−NP promoted side reactions to form lower hydrocarbons and carbon, which caused catalyst deactivation. In‐situ DRIFTS analysis revealed the interaction of propane and propylene gases with the catalyst, which was an important revelation to find the source of carbon deposition.

Ruthenium/cobalt binary oxides supported on hollow alumina microspheres as highly efficient catalyst for vinyl chloride oxidation

Alumina hollow microspheres (Al2O3-hms) were synthesized and used to support metal oxide and binary metal oxide particles to prepare three catalysts, designated as RuOx/Al2O3-hms, CoOx/Al2O3-hms and RuCoOx/Al2O3-hms. Their catalytic properties in vinyl chloride oxidation were investigated and found to follow this order: RuCoOx/Al2O3-hms > RuOx/Al2O3-hms > CoOx/Al2O3-hms. In comparison with a commercial Al2O3 support, the Al2O3-hms provide a higher specific surface area and unique hollow spherical morphology, benefiting for uniform distribution of catalyst particles. It was also found that the strong metal-support interaction between metal nanoparticles and Al2O3-hms has significant effects on the low-temperature reducibility, the surface oxygen abundance and mobility, giving rise to different oxidation activities. The Al2O3-hms supported metal catalysts remained relatively high catalytic activity after consecutive catalytic runs and high-temperature annealing. The anti-sintering ability enhancement of metal particles was attributed to the stabilization and metal-support interaction effects with Al2O3-hms.

Tailoring performance of Co–Pt/MgO–Al2O3 bimetallic aerogel catalyst for methane oxidative carbon dioxide reforming: Effect of Pt/Co ratio

Co–Pt/MgO–Al2O3 bimetallic aerogel catalysts were synthesized via a sol-gel combined with supercritical drying method. The catalysts were characterized by XRD, BET, HRTEM, STEM-HAADF, XPS, H2-TPR, H2-TPD, TG/DSC, FESEM and their catalytic performances in CH4 oxidative CO2 reforming were evaluated. The H2 spillover effect between Pt and Co enhanced the reducibility of the catalyst, while the strong metal-support interaction (SMSI) effect in the bimetallic aerogel catalysts confined the agglomeration of metal particles. Pt/Co ratio played a key role on the existence of surface metal species, leading to different catalytic performances. The optimal Pt/Co ratio was Pt/Co = 0.02 w/w, on which a 50% higher activity in terms of CH4 conversion than monometallic Co or Pt aerogel catalysts was obtained. Whereas the impregnated catalyst with an identical composition showed a much lower activity. The Co–Pt aerogel catalysts also showed high resistance to inactive carbon formation. The oxidation temperature of the carbon species deposited on the spent Co–Pt aerogel catalyst was only 275 °C and no filamentous or graphitic carbon was identified, disclosing that the formation of inactive carbon was inhibited due to the synergy between Co and Pt and the SMSI effect.

Active and stable Pt-Ceria nanowires@silica shell catalyst: Design, formation mechanism and total oxidation of CO and toluene

Cerium oxide is one of the most important rare earth metal oxides in catalysis, however, the sintering problem of noble metals and CeO2 at higher temperature (e.g., >700 °C) is still unresolved. Herein, Pt nanoparticles self-assembled on ultra-thin CeO2 nanowires (NWs) and then confined inside a thermally robust porous silica shell (Pt-CeO2NW@SiO2) were introduced. The thickness of CeO2 NWs was just ˜2.0 nm. Moreover, Pt-CeO2 NW@SiO2 showed significantly enhanced catalytic performances for total oxidation of CO and toluene. The increased catalytic properties are attributed to the strong metal-support interaction effect between Pt and CeO2 NWs at sub-nanoscale. Most importantly, the special core-shell structure also affords excellent sintering resistance retention up to 700 °C for 100 h, due to the guarding effect of porous silica shell. Finally, the formation mechanism of Pt-CeO2 NW@SiO2 was investigated in detail. Current strategy should inspire many rational designs of rare-earth metal-based nanocatalysts for real-world catalysts.

Effect of Mo promotion on the activity and selectivity of Ru/Graphite catalysts for Fischer-Tropsch synthesis

In this paper molybdenum oxide promoted graphite supported ruthenium catalysts highly active and selective for Fischer-Tropsch synthesis (FTS) are presented. The effect of Mo loading (0–5 wt%) of promoted graphite supported Ru (2 wt%) catalysts on the syngas conversion was studied at 523 K, H2/CO = 2 and 3.5 bar. Mean diameters of Ru nanoparticles were all close to 3 nm independently of the molybdenum loading used. Microcalorimetric measurements during CO adsorption at 330 K reveal a clear interaction between Ru and Mo observing an important increase of CO adsorption heats for Mo/Ru ratios of ≤0.26. XPS analysis performed to 2Ru0.5Mo/G catalyst after in-situ reduction showed the presence of MoVI (MoO3) and MoIV (MoO2) species on the catalyst surface. It is argued that these Mo species could be located around the ruthenium nanoparticles acting as Lewis acids and therefore facilitating the CO dissociation. Mo promotion increased up to four times the activity with respect to unpromoted Ru catalyst, increased the selectivity to C5+ products and improved the olefin to paraffin ratio in the C2-C3 hydrocarbons range. These conclusions contribute to understand the Mo promotion effect in the FTS, because realistic deductions have been obtained using a proper inert support for studying the molybdenum promotion effect in ruthenium based catalysts, avoiding strong metal-support interaction effects.

Light-Triggered Boost of Activity of Catalytic Bola-Type Surfactants by a Plasmonic Metal-Support Interaction Effect.

The maximization of activity is a general aim in catalysis research. The possibility for light-triggered enhancement of a catalytic process, even if the process is not photochemical in nature, represents an intriguing concept. Here, we present a novel system for the exploration of the latter idea. A surfactant with a catalytically active head group, a protonated polyoxometalate (POM) cluster, is attached to the surface of a gold nanoparticle (Au NP) using thiol coupling chemistry. The distance of the catalytically active center to the gold surface could be adjusted precisely using surfactants containing hydrocarbon chains (Cn) of different lengths (n = 4–10). Radiation with VIS-light has no effect on the catalytic activity of micellar aggregates of the surfactant. The situation changes, as soon as the surfactants have been attached to the Au NPs. The catalytic activity could almost be doubled. It was proven that the effect is caused by coupling the surface plasmon resonance of the Au NPs with the properties of the POM head group. The improvement of activity could only be observed if the excitation wavelength matches the absorption band of the used Au NPs. Furthermore, the shorter the distance between the POM group and the surface of the NP, the stronger is the effect. This phenomenon was explained by lowering the activation energy of the transition state relevant to the catalytic process by the strong electric fields in the vicinity of the surfaces of plasmonic nanoparticles. Because the catalytic enhancement is wavelength-selective, one can imagine the creation of complex systems in the future, a system of differently sized NPs, each responsible for a different catalytic step and activated by light of different colors.

Metal-support interaction controlled migration and coalescence of supported particles

The particle migration and coalescence (PMC) kinetics of a supported metal are the main deactivation mechanisms restricting the successful industrialization of nanoparticles, but the theoretical insights regarding these kinetics are lacking. One key issue is the lack of a physical model to predict the effects of metal-support interaction (MSI) on PMC kinetics. In this paper, we report a theoretical study of PMC kinetics and their dependence on MSI. A new particle diffusion model is proposed based on the surface premelting hypothesis that considers the contact angle of a hemispherical particle on the support. Enhanced MSI suppresses PMC by increasing the radius of curvature and the interfacial adhesion energy, even though the accompanying reduction in the geometry factor partially promotes PMC kinetics. The increased surface energy increases the chemical potential of the atoms in the particle, which is conducive to PMC; an increased surface energy also results in enhanced MSI, which suppresses PMC. The competition between these two contradictory effects leads to a critical contact angle where the surface energy has no influence on the diffusion and resulting PMC kinetics. The proposed diffusion theory mode lincluding the effects of the support and the corresponding kinetic simulations, shed light onto the support-dependence of PMC kinetics and provide a foundation for further optimization and design of supported particles with better stability.

Steam reforming of n-dodecane over mesoporous alumina supported nickel catalysts: Effects of metal-support interaction on nickel catalysts

Developing a highly active and stable Ni-based catalyst is still a challenge for the generation of on-site hydrogen through steam reforming of long-chained hydrocarbons, such as kerosene fuels. Ni nanoparticles (ca. 5 nm) on mesoporous alumina prepared by atomic layer deposition (ALD) were employed in steam reforming of n-dodecane, and exhibited a turnover frequency (TOF) of 477.6 h−1, whereas Ni nanoparticles on commercial alumina support prepared by impregnation method exhibited a TOF of 100 h−1. The high activity of ALD Ni catalysts was ascribed to high reduction degree, as confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), and H2-chemisorption. A deactivation was also observed on the ALD prepared catalysts, which was ascribed to the weak metal-support interaction, as confirmed by H2 temperature-programmed reduction (TPR). The ALD Ni/Al2O3 catalysts were further modified with CeO2 and they showed enhanced stability with 8% deactivation degree in steam reforming of n-dodecane. Further characterizations of spent catalysts showed that the presence of CeO2 was favorable for stabilizing Ni nanoparticles by enhancing moderate metal-support interaction, and reducing the formation of coke on the interfaces of NiCeO2.

Core-shell structure Ag@Pd nanoparticles supported on layered MnO2 substrate as toluene oxidation catalyst

The silver palladium bimetallic core-shell structure nanoparticles (Ag@Pd NPs) were synthesized by a thin Pd shell slowly generating on the outmost of Ag nanoparticle according to galvanic replacement mechanism. Then, the 2D layered structure manganese dioxide (MnO2) substrate was used to support the as-synthesize Ag@Pd NPs to prepare Ag@Pd/MnO2 catalyst for toluene purification in oxidation reaction. Physicochemical properties of the samples were characterized by a number of different analytical techniques. It is found that the Ag@Pd NPs are homogeneously spherical shape with an average particle diameter size of 7.1 nm. And the MnO2 substrate can not only uniformly disperse Ag@Pd active component on its surface for its high specific surface area and mesopore volume, but also provide the reactive lattice oxygen by its mixed oxidation states of Mn3+/Mn4+. Moreover, the core-shell configuration of Ag@Pd NPs can improve the state phase transformation from Pd0 to PdO2 with the aid of lattice oxygen of MnO2 substrate, because of the lattice oxygen migration controlled strong metal-support interaction (SMSI) effect between palladium active component and MnO2 substrate. So, there would be more exposed PdO2 active sites on the Ag@Pd/MnO2 catalyst relative to monometallic Pd/MnO2 catalyst. Hence, the as-prepared bimetallic core-shell Ag@Pd/MnO2 catalyst exhibits greatly higher toluene oxidation activity at lower reaction temperature than monometallic Pd/MnO2 catalyst, indicating it is a promising catalyst for use in volatile organic compounds (VOCs) purification.