Surface Of Metal Particles Research Articles

Nanoengineered Injectable Hydrogel: An Advanced Radioprotective Barrier with Magnetic Hyperthermia Synergy.

Despite its effectiveness in eradicating cancer cells, current tumor radiotherapy often causes irreversible damage to the surrounding healthy tissues. To address this issue and enhance therapeutic outcomes, we developed a multifunctional injectable hydrogel that integrates electromagnetic shielding and magnetothermal effects. This innovation aims to improve the efficacy of brachytherapy while protecting adjacent normal tissues. Recognizing the limitations of existing hydrogel materials in terms of stretchability, durability, and single functionality, we engineered a composite hydrogel by self-assembling nickel nanoparticles on the surface of liquid metal particles and embedding them into an injectable hydrogel matrix. The resulting composite material demonstrates superior electromagnetic interference shielding performance (74.89 dB) and a rapid magnetothermal heating rate (10.9 °C/min), significantly enhancing its in vivo applicability. The experimental results confirm that this innovative nanocomposite hydrogel effectively attenuates electromagnetic waves during brachytherapy, thereby protecting normal tissues surrounding the tumor and enhancing radiotherapy efficacy through magnetothermal therapy. This study advances the safety and effectiveness of cancer treatments and provides new insights into the development of multifunctional biomedical materials, promoting the innovative application of nanotechnology in the medical field.

An optimised cell for in situ XAS of gas diffusion electrocatalyst electrodes

The quality of in situ XAS of electrochemical systems is highly sensitive to electrode disturbances, such as gas evolution and gas consumption at an electrolyte / catalyst interface. A novel in situ spectro‐electrochemical X‐ray absorption spectroscopy cell is presented as a new tool for the characterisation of gas evolving and consuming electrocatalysts at high overpotentials. By utilising a thin, porous membrane with efficient electrolyte and gas circulating loops, an improved three phase interface that enabled efficient gas supply and minimised the interference from bubble formation. X‐ray absorption spectroscopy measurements were conducted in fluorescence mode with three experiments selected to demonstrate the cell’s performance. The first two reactions; an in‐situ study of a highly active amorphous iridium oxide catalyst during the oxygen evolution reaction and an in‐situ study of copper oxide during the carbon dioxide reduction reaction are used to exemplify the XAS data quality achieved under operational conditions. Thirdly, a detailed XAS investigation of a highly dispersed platinum catalyst during the oxygen reduction reaction is presented, along with comparative data in nitrogen. These measurements show the retention of oxygen on the surface of the platinum metal particles down to 0.48 V (vs. RHE), well below the platinum oxide reduction peak.

Effect of Subtle Changes in Ni2+/Ni3+ and Particle Surface Area in LiNi0.5Mn0.5−xCoxO2 (x = 0.1–0.3) Cathode Materials for Lithium-Ion Batteries

In Li[Ni,Mn,Co]O2 (NMC) cathode materials, small changes in transition metal ratio and particle surface area can significantly impact capacity retention. To understand the combined effect of transition metal ratio and the particle surface area, we studied LiNi0.5Mn0.5−xCoxO2 (x = 0.1–0.3) particles with two different morphologies: dense, spherical particles and high-surface area aggregates. All compositions in this series contain the same percentage of Ni but have differing amounts of Ni2+ and Ni3+. While Ni2+ tends to induce anti-site defects predominantly in the bulk, Ni3+ promotes particle surface reconstruction, both of which negatively impact capacity retention. Upon cycling to 4.4 V for 100 cycles, we observe that particles of high surface area with high Ni3+ concentration undergo the most severe capacity degradation. However, high surface area particles with high proportion of anti-site defects undergo sluggish capacity fade. Overall, with 60% of Ni2+ and 40% of Ni3+, spherical NMC 532 particles endure the detrimental effects of anti-site defects and surface reconstruction, but neither too prominently and thus emerges as the best candidate among the studied samples. This study highlights the synergy between transition metal ratio and particle surface area and how it determines the properties of the NMC cathode materials.

Simulation of effect of metal particles on breakdown process of three-electrode gas spark switches

Compared with two-electrode gas spark switch, three-electrode gas spark switch has the advantages of lower operating voltage, higher reliability and less discharge jitter, so it has been widely used in pulse power systems. However, due to the characteristics of pulse power technology, the gas spark switch is easy to cause ablation on the electrode surface during use, and the metal particles generated by ablation will significantly affect the stability and reliability of the switch. In this work the discharge process of the three-electrode gas spark switch under atmospheric pressure nitrogen environment is simulated first. In this model, the ionization coefficient near the trigger electrode is modified to compensate for the shortcomings of the local field approximation, and the relevant mathematical derivation process is given. The formation of the initial electrons is described by the field electron emission phenomenon, and the development process of electron collapse into the streamer is obtained. The physical mechanism of switch on is investigated, and the development process of each stage of switch discharge is described in detail. Then, the discharge process of the switch is studied when there are metal particles near the trigger. The study shows that the presence of metal particles enhances the electric field near the trigger and accelerates the formation of the initial electron cloud. In addition, in the presence of metal particles, the metal particles and the trigger will first break down, forming a high-density plasma channel after the breakdown, and becoming the source of the subsequent flow development. At the same time, because the metal particles on the channel have an obstructing effect on the streamer development, the streamer generates a discharge branch after contacting metal particles. In the end, the influences of metal particles of different shapes and sizes on the discharge process are discussed. The results show that metal particles with sharp shapes have stronger electric field distortion, when the electric field intensity is large enough, it may cause field emission on the surface of metal particle. And it is also made clear that the size of metal particle is small, the obstruction of the development path of streamer is small, and the streamers quickly converge behind the particles.

Ultrafine design of carbon whisker array @ hollow carbon sphere anode for superior K-storage

Even though bottom-up strategy has been successfully developed to construct nanocarbon materials from molecule blocks for energy storage applications, elaborate structure manipulation via a facile and scalable method remains a big challenge. Herein, a facile free-radical C–C coupling-based bottom-up strategy was proposed to controllably construct carbon whisker array @ hollow carbon sphere (CWA@HCS) anode from the molecule block of hexabromobenzene (HBB) for superior K-storage. The novel CWA@HCS anode was easily achieved via the controllable catalysis of C–C coupling reaction on the surface of commercial metallic Cu particles. The optimized CWA@HCS anode delivered a high reversible K-storage capacity of 367.6 mAh/g at 50 mA/g, excellent rate capability (155.5 mAh/g at 1000 mA/g), and excellent long-term cycle performance (182.5 mAh/g maintained after 700 cycles at 500 mA/g). In addition, the full cell assembled from CWA@HCS electrode showed excellent cycle performance and rate performance. These excellent K-storage properties should be attributed to the surface capacitive-dominated K-storage mechanism guaranteed by the three-dimensional (3D) array structure. This study provides a basic reference for the design of advanced nanocarbon materials as well as anode materials for potassium ion batteries.

Microwave sintering of Ti(C,N)-based cermets: Study of the magnetic effect on metal phase

For microwave heating of Ti(C,N)-based cermets, this paper presents a microwave heating simulation study of pure Ti(C,N) ceramics and Ti(C,N)-based cermets using Comsol software. S-parameter inversion is employed to determine the equivalent relative permittivity of Ti(C,N)-based cermets with varying metal contents. The pairwise Ni metal plate model is utilized to investigate the law of mutual coupling voltage between metal plates. It was found that vigorous electric field intensity is generated around the metal particles of Ti(C,N)-based cermets, and high electric field intensity is generated between the metal particles. Model slice analysis and mechanism analysis are combined to reveal the following phenomena: (1)The surface of metal particles in Ti(C,N)-based cermets excites induced electromagnetic fields; (2)High mutual coupling voltages are generated between metal particles; (3)The reflection effect of metal particles on microwaves can increase the electric field intensity between metal particles. By statistically analyzing the temperature data of pure Ti(C,N) ceramics and Ti(C,N)-based cermets during the initial 30-min microwave sintering period, the temperature difference changing law can be concluded: (1)During the initial 30 min of microwave sintering, the temperature difference between the two gradually increased with time; (2)At 30 min, the temperature difference between the two reached 111 °C.

Insights into the structure–activity relationship in aqueous-phase hydrogenation of levulinic acid to 1,4-pentanediol over bimetallic Ru-Re/C catalysts

Hydrogenation of biomass-derived levulinic acid (LA) to 1,4-pentanediol (PDO) is a sustainable route to replace petroleum-derived polyols. Although the combination of ruthenium (Ru), a hydrogenating metal, and rhenium (Re), an oxophilic promoter, results in high activity for PDO production, the synergistic effect between Ru and Re and the effect of carbon support are not well understood. In this study, the factors determining the catalytic activity and selectivity of carbon-supported RuRe for PDO production were investigated. Bimetallic RuRe nanoparticles with various atomic ratios and monometallic Ru and Re were supported on various carbon materials with different surface properties such as activated carbon (AC), carbon black (CB), mesoporous carbon (CMK-3), carbon nanofiber (CNF) and their reaction kinetics were compared. The structural and physicochemical properties of the catalysts were characterized using X-ray diffraction, temperature-programmed reduction, N2-physisorption, transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalytic activity and PDO selectivity were correlated with the metal particle size, pore structure, and surface oxygen functionalities, in which the smaller RuRe nanoparticles with a Re-enriched surface supported on carbon with a larger pore size exhibited a higher PDO production rate. Among the catalysts, RuRe supported on CB exhibited the highest PDO selectivity (∼75 %) at 130 °C and 50 bar-H2. The impact of the Re promoter in the RuRe/C catalyst on the LA hydrogenation mechanism was also investigated for the first time using in situ FT-IR spectroscopy.

Quantitative Analysis of the Interface between Titanium Dioxide Support and Noble Metal by Electron Energy Loss Spectroscopy.

The interface structure of supported catalysts plays a significant role in the strong metal-support interactions (SMSI). However, it remains limited on interpreting interface structures, thus affecting the understanding of SMSI origin and impact on catalytic performance. Herein, electronic energy loss spectroscopy was adopted to characterize the interface microstructures of Pt/TiO2 materials. After high-temperature reduction processing, it was observed that the coating on the surface of the Pt metal particles was TiOx. Then, based on Gaussian function fitting, an effective and valid method was established for quantitative analysis on Ti L edge loss spectrum. This method allowed us to accurately determine the stoichiometric number of TiOx phases. In order to probe the classical phenomenon of strong metal-support interactions in more detail, we also discussed and analyzed the origin of TiOx and its effect on the electronic structure of the material using density functional theory calculations. The structure of surfaces and interfaces as well as the chemical evolution of supported catalysts on a microscale have been revealed, thereby providing a new analysis method and research perspectives for the future study of metal-support interactions.

Effect of Metal Ions and Suspended Particles on Streamer Propagation

Metal contamination in insulating oil is one of the main threats to the safe and reliable operation of oil-immersed equipment such as on-load tap changers. The mechanism analysis of metal ions’ influence on the discharge process of insulating oil is rarely involved in previous studies. Herein, the generation mechanism of metal ions and suspended particles is summarized first for subsequent modeling. Numerical models are constructed to simulate the streamer propagation in oil, considering the effect of two forms of metal contaminant. The dissociation source term of ionic compounds is introduced into the charge continuity equation to elucidate the impact of metal ions on streamer propagation. The results reveal that adding metal ions increases the overall speed of the streamer and decreases the maximum field intensity at the head of the steamer compared to pure oil conditions. Excessive ion concentration hinders the streamer’s development by creating the space charge shielding effect. Charge accumulation on the surface of suspended metal particles is the leading cause for the branching or turning of the streamer channel. The size, quantity of the metal particles, and the landing location will significantly affect the streamer propagation characteristics, e.g., the landing location on the surface of the metal particle will determine whether the subsequent branching streamer head can further develop. The results contribute to a better understanding of the influence of ionic and particulate metal contaminants on the microscopic discharge process in insulating oil.

Current and friction transients during tribocorrosion of a biomedical titanium alloy sliding against zirconia

The tribocorrosion mechanisms of a Ti–Nb–Zr–Ta (TNZT) alloy rubbing against a zirconia ball in a Phosphate Buffered Solution (PBS) were analyzed by considering the mechanical and chemical interactions that lead to the material degradation. To understand the governing mechanisms, tribocorrosion tests were carried out in a ball on flat contact and reciprocating tribometer applying two normal loads (6.7 and 11.2 N) and two different anodic potentials (400 and 1500 mV). Worn surfaces were characterized by SEM and FIB cross sections as well as surface analysis. During the tribocorrosion tests, transients consisting in simultaneous abrupt current increase and a decrease in the COF were found at different instants of the tests. Subsurface cracking as well as third body build up were observed. These different phenomena and their temporal sequence could be described by initial sliding tribocorrosion, including metal particle removal and surface oxidation, followed by the build-up of a protective third body. After a certain number of sliding cycles subsurface cracking due to strain accumulation beyond a critical level lead to the detachment of a large particles that reactivated the initial tribocorrosion process. This mechanistic view could be substantiated by a model based on a quantitative analysis of the results.

Comprehending Metal Particle Combustion: a Path Forward

AbstractThe paper discusses the physics required for accurate modeling of metal particle combustion and includes aspects previously neglected. Specifically, three physical phenomena are emphasized: 1) internal boiling on the condensed oxide‐metal interface; 2) condense‐luminescent loss during nano‐oxide formation; and, 3) suppressed heat transfer on the metal particle surface due to a low energy accommodation coefficient (EAC) are essential. The last two phenomena were explored in previous work. Internal particle interface boiling detailed in the current work enables the semi‐heterogeneous combustion of Al particles, an important process needing attention for accurate modeling. The interface boiling mechanism allowing for the semi‐heterogeneous combustion explains a number of experimental puzzles related to metal particle combustion. In particular, the semi‐heterogeneous combustion justifies the coexistence of two burning regimes of Al particles (slow and fast) recently observed. Based on reported findings, revising current numerical models for metal particle combustion to include these three physical phenomena is necessary. Implications toward enhancement of energetic performance for metal‐containing formulations are also discussed.

Synthesis of Secondary Monoalcohols from Terminal Vicinal Alcohols over Silica-Supported Rhenium-Modified Ruthenium Catalyst

The selective synthesis of secondary alcohols from 1,2-alkanediol by C–O hydrogenolysis, which has been less investigated than the synthesis of primary alcohols, was investigated with Ru-based catalysts and 1,2-propanediol (1,2-PrD) as a model substrate. The modification of Ru/SiO2 with ReOx achieved significant improvement of activity. The hydrogenolysis of 1,2-PrD over Ru–ReOx/SiO2 (Re/Ru = 0.5) initially formed both 2-propanol (2-PrOH) and 1-propanol (1-PrOH) with similar selectivity along with the formation of ≤ C2 compounds, and then 1-PrOH was preferably converted to propane; as a result, only 2-PrOH remained in the liquid phase with 23% yield at longer reaction time. This catalyst was reusable at least twice. The characterization with H2-TPR, XRD, TEM-EDX, XANES, and EXAFS showed that the Ru species in the Ru–ReOx/SiO2 catalysts were completely reduced in the reaction conditions, while a part of Re species were also reduced to partially reduced monomeric species (Reδ+Ox) without Re–Re direct bond located on the surface of Ru metal particles. This ReOx-modified Ru metal surface probably works as the active sites. The excess Re species was reduced to large Re metal particles; however, these Re metal particles are not involved in the catalysis.

INFLUENCE OF ACID AND CO-CATALYST ON PHOTOCATALYTIC HYDROGEN PRODUCTION

In recent years, the use of fossil fuels such as oil, coal and natural gas has increased along with the advanced economic activities of developed countries, resulting in urban air pollution, acid rain due to NOX and SOX, acid fog and carbon dioxide (CO2) emissions, as a result global warming issue becomes hot issue for all international organizations. On the other hand, there is an urgent need to introduce new environmentally friendly energy. New clean energy includes renewable energy such as solar power, wind power, geothermal power, ocean, hydropower, and hydrogen energy has been attracting significant attention in recent years. In this work hydrogen production by using different acid solutions and different co-catalysts were successfully achieved. Maximum production was 1767 μmol g-1 when Pd was used and 2229 μmol g-1 when oxalic acid was applied. The mechanism could be attributed to that promotion of hydrogen production on the surface of metal particles (Pd) can be considered. This is because the electrons that have moved to the conduction band move from the top of TiO2 onto the surface of the co-catalyst particles, as a result promotes the reduction reaction and improves the ability to generate hydrogen.

Surface coating preparation of spherical magnetic materials

Magnetic materials are being increasingly used in anti-counterfeiting coatings, but the dark colors of magnetic materials greatly limit their applications. This necessitates the development of light-colored magnetic materials. In this study, the heterogeneous precipitation method was used to deposit a layer of titanium dioxide (TiO2) on the surface of magnetic spherical metal particles, followed by the deposition of a layer of Ag by the reduction method, in order to achieve a light color. In the experiment, the particles were initially coated with a few tens of nanometers of TiO2 with a strong shading effect, followed by a further coating of Ag of the same thickness with a similar shading performance. Not only did this achieve a lighter color, but there was no reduction in the magnetic properties of the material after the application of the coating. Scanning electron microscopy (SEM), scanning electron microscopy and energy-dispersive spectroscopy (SEM-EDS), X-ray diffractometry (XRD), and other methods were used to study the changes in morphology and composition before and after the magnetic material was coated. A magnetic tester was used to study the changes in magnetic strength before and after the magnetic material was coated.

Nonoxidizing heating of chip‑powder dispersions of ferrous metals in hydrocarbon atmosphere

The process of inorganic and organic components temperature transformation of metal waste into solid and gaseous products in a continuous hot briquetting muffle furnace has been studied. The composition of the hydrocarbon atmosphere formed in the muffle under conditions of limited access to the oxidizer has been determined. It is shown that the thermal destruction of the coolant oil phase proceeds according to a complex mechanism of consecutive reactions, including polycondensation, polymerization, and deep compaction with a constant decrease in the hydrogen content and ends with the formation of a coke‑like carbon residue on the surface of metal particles and an air suspension of finely dispersed carbon particles (smoke). When it is heated to hot briquetting temperatures of 750–850 °C, chemically active dispersions of ferrous metals are protected from oxidation first by a hydrocarbon gas with a density of 9.0–13.5 kg/m3, then by a pyrocarbon coating with a thickness of 0.1–0.3 mm up to the completion of the processes of pressing and cooling the briquette.

Glucosamine to gold nanoparticles binding studied using Raman spectroscopy

The binding of glucosamine to gold in water solutions of glucosamine hydrochloride mixed with clean colloidal gold nanoparticles obtained by laser ablation in liquid was studied using surface-enhanced Raman scattering (SERS), dynamic light scattering (DLS) and UV–VIS spectroscopy. The purpose of this study was to establish whether the binding of charged aminogroup to gold nanoparticles (AuNPs) is taking place, and if it does, how can it be identified by means of SERS.The average size of dried gold nanoparticles was (20 ± 4) nm determined by averaging the sizes observed in transmission electron microscopy micrographs, which is smaller than the average size of gold nanoparticles in water solution as determined by DLS: (52 ± 2) nm. Upon adding the glucosamine solutions to gold colloid, average hydrodynamic diameter of ions was slightly larger for 0.1 mM glucosamine solution (55 ± 2 nm), while it increased to (105 ± 22) nm in the case of 1 mM solution, and was (398 ± 54) nm when 10 mM glucosamine solution was added.Most prominent Raman bands observed both for 0.1 mM and 1 mM glucosamine solutions were located at 1165 cm−1, 1532 and 1586 cm−1 and assigned to C-N coupled with C-C stretching, and C-NH3+ deformation angles bending. In SERS spectrum of 1 mM GlcN+ solution, two strong bands at 999 and 1075 cm−1 were found and attributed to C-Oring stretching coupled with C-NH3+ bending (999 cm−1) and to dominantly C-O stretching vibration. The differences in SERS spectra are attributed to different number of glucosamine molecules that attach to gold nanoparticles and their orientation with respect to the metal particle surface, partly due to presence of beta anomers protonated at anomeric oxygen position. The assignment of glucosamine bands was further corroborated by comparison with vibrational spectra of alpha and beta glucose and of polycrystalline powder of glucosamine hydrochloride. For all three substances comprehensive calculation of vibrational density of states was conducted using density functional theory. Benchmark bands for polycrystalline glucose anomers distinction are 846 and 915 cm−1 for alpha glucose, and 902 cm−1 for beta glucose. However, the bands observed in SERS spectra of 0.1 mM glucosamine solution at 831, 899, and 946 cm−1 or in 1 mM solution at 934 cm−1 cannot be easily identified as belonging either to alpha or beta glucosamine anomer, due to complexity of atomic motions involved. The identification of vibrational bands associated with –CNH3+ group will aid SERS studies on amino acids, especially in cases when several atomic groups could possibly bind to AuNPs.

Adsorption of Keggin-Type Polyoxometalates on Rh Metal Particles under Reductive Conditions.

The adsorption of POMs on Rh/SiO2 in water solvent under strongly reductive conditions was investigated. Aqueous solutions of α-Keggin type silicotungstate and silicovanadotungstates were mixed with Rh/SiO2 at 393-473 K under 1 MPa of H2. Monovanadium-substituted silicotungstate, α-SiVW11O405- (SiVW11), was more readily adsorbed than nonsubstituted silicotungstate, α-SiW12O404- (SiW12). After adsorption at 433 K, SiVW11 was desorbed from Rh/SiO2 by oxidation with Br2 water without change of the Keggin structure, as evidenced by 51V NMR. Trivanadium-substituted silicotungstate, α-1,2,3-SiV3W9O407-, was not stable, and the desorbed species from Rh/SiO2 by oxidation with Br2 did not maintain the Keggin structure. The very high temperature for adsorption (473 K) also led to the decomposition of the Keggin structure of SiVW11. An increase in the concentration of SiVW11 in the liquid phase gave a saturation of the amount of desorbable SiVW11, up to five SiVW11 anions per one Rh particle with a 3 nm size. The elemental analysis and W L3-edge extended X-ray absorption fine structure of Rh/SiO2 after the adsorption of SiVW11 showed that a part of SiVW11 was decomposed and irreversibly adsorbed as metallic W species incorporated into the surface of Rh metal particles. The amount of decomposed SiVW11 was almost the same as that of SiVW11 adsorbed as the original Keggin structure. The desorbable SiVW11 was probably bonded on the W atom incorporated on the Rh metal particles as the two-electron-reduced form (α-SiVIIIW11O407-).

Metal particle induced spacer surface charging phenomena in direct current gas-insulated transmission lines

The interpretation of the surface charge pattern of spacers in gas-insulated transmission lines (GIL) is a research topic with great importance, which requires a comprehensive understanding of charge behaviors at physical interfaces. Here, we report a surface charging phenomenon of spacers in the presence of metal particles inside the direct current (DC) GIL. The charging of spherical metal particles on the spacer surface appears as dotted discontinuously distributed charge spots, which are due to the charge injection from the induced charge of the metal particle and gas ionization over the metal particle surface. Concentrically distributed bipolar charge patterns are seen to build up, which are due to the surface trapping of charges from gas ionization at the end tip of the acicular metal particle. The lateral type of ionization obeys the law of dielectric barrier discharge of the needle-plate electrode in an intense DC electric field, which may bring significant influence on the safety of the spacer. The study in this letter provides direct evidence demonstrating the surface charge patterns of spacers in the presence of metal particles, which serves as an important basis for the design of DC GIL.

Metal effect pigments

AbstractMetal effect pigments are luster pigments consisting of platelet-like metallic particles, mostly of aluminum (so-called silver bronzes), copper, copper/zinc (so-called gold bronzes), and zinc flakes. After parallel orientation in their application medium, they show a metal-like luster by reflection of light at the surface of the flat metal particles in one direction. Thus, the pigment particles act similar to small mirrors and lead when orientated parallel in the application system to a reflecting metal luster (metallic effect). Metal effect pigments are used in all relevant application systems such as coatings, paints, plastics, artist paints, cosmetics, printing inks, leather, construction materials, paper, glass, and ceramics. Specific composition, particle size distribution and surface quality determine the coloristic and application technical properties of the individual pigments. Many pigments are coated with a specific surface treatment to improve the quality concerning the stability and the compatibility with the application system. Metal effect pigments are offered in form of powders, pastes, pellets, suspensions or color concentrates. They are manufactured starting from a metal granulate (grit), which is ground under formation of flakes.

Calculation and analysis of the amount of secondary component products of NOX and SO2 on metal oxide surface based on Drifts simulation: A case study of vehicle exhausts emission

In this paper, the micro reactions of SO2 and NOx in the metal oxides (Fe2O3, MgO, MnO2, Al2O3, ZnO, Cuo, SiO2 and Cr2O3) from vehicle exhaust are studied by diffuse reflectance infrared spectroscopy (DRIFTS). The amount of secondary component in PM2.5 is analyzed by observing the synergistic or antagonistic effects of different gases on the surface of different metal oxides. The results show that when SO2 and NO2 coexist, the formation of sulfate is greatly promoted on the surface of Fe2O3 metal particles, and the intermediate sulfite is formed at the initial stage and then rapidly oxidized to sulfate. Under the condition of oxygen enrichment, the total species content of secondary components of fine particles formed on the surface of metal oxides is Cr2O3 > Fe2O3 > MgO > MnO2 > Al2O3 > ZnO > CuO > SiO2. because Cr2O3 has a strong ability to adsorb and activate acid gas, so the content of surface species generated in the micro reaction is more than that of other metal oxides; the metal oxides containing iron, magnesium and manganese can more effectively convert SO2 into sulfate in the presence of NOx, but the sulfate generated on the surface of Cr2O3, CuO and Al2O3 decreases, which leads to the difference of metal oxide activity It is caused by the change of metal surface properties. This result has a certain guiding significance for the reaction of SO2 and NOx to metal oxides emitted by motor vehicles in the atmosphere.