Modified Impregnation Method Research Articles

Does the active surface area determine the activity of silica supported nickel catalysts in CO2 methanation reaction?

Two series of silica supported catalysts with comparable nickel contents varying from 2.5 to 20 wt.% were prepared by wet impregnation method in the absence and presence of citric acid in the impregnation solution. Temperature-programmed reduction, X-ray diffraction and electron microscopy studies indicated changes of reducibility of nickel oxide species in the corresponding catalysts and formation of nickel nanoparticles of different size and morphology. A gradual increase in the performance of catalysts in the CO2 methanation reaction was observed with increasing Ni loading. The application of a modified impregnation method led to a reduction in the size of the nickel crystallites, which increased the active surface area of the catalysts, improving their activity and selectivity towards methane at low temperatures, as well as their stability at high temperatures. It was shown that the high active surface area of silica-supported nickel catalysts, due to the presence of small crystallites, is a key factor in increasing their activity. However, other catalyst properties may also play an important role. Hydrogen temperature-programmed desorption and in-situ DRIFTS adsorption/desorption of CO, CO2 and CO2 hydrogenation reaction studies indicated that modification of the method of catalyst synthesis led to changes in the surface properties of the catalysts, affecting the way CO2 and H2 activation and the transformation of resulted intermediate species to the final reaction products.

Scalable Solid-State Synthesis of Carbon-Supported Ir Electrocatalysts for Acidic Oxygen Evolution Reaction: Exploring the Structure-Activity Relationship.

Enhancing iridium (Ir)-based electrocatalysts to achieve high activity and robust durability for the oxygen evolution reaction (OER) in acidic environments has been an ongoing mission in the commercialization of proton exchange membrane (PEM) electrolyzers. In this study, we present the synthesis of carbon-supported Ir nanoparticles (NPs) using a modified impregnation method followed by solid-state reduction, with Ir loadings of 20 and 40 wt % on carbon. Among the catalysts, the sample with an Ir loading of 20 wt % synthesized at 1000 °C with a heating rate of 300 °C/h demonstrated the highest mass-normalized OER performance of 1209 A gIr-1 and an OER current retention of 80% after 1000 cycles of cyclic voltammetry (CV). High-resolution STEM images confirmed the uniform dispersion of NPs, with diameters of 1.6 ± 0.4 nm across the support. XPS analysis revealed that the C-O and C═O peaks shifted slightly toward higher binding energies for the best-performing catalyst. In comparison, the metallic Ir state shifted toward lower binding energies compared to other samples. This suggests electron transfer from the carbon support to the Ir NPs, indicating a potential interaction between the catalyst and the support. This work underscores the strong potential of the solid-state method for the scalable synthesis of supported Ir catalysts.

CuO/CeO2 catalysts prepared by modified impregnation method for ethyl acetate oxidation

The impregnation method is one of the most popular methods for preparing various types of supported catalysts. However, the preparation of highly active catalysts by the conventional impregnation method is still a great challenge. In this paper, a modified impregnation method (MI) was developed to prepare CuO/CeO2 catalysts for the catalytic oxidation of ethyl acetate (EA). It was found that the 5 %CuO/CeO2 catalyst (5-MI-500) prepared by MI method achieves 100% EA conversion at a low temperature of 200 °C. However, the temperature for 100% EA conversion over the 5 %CuO/CeO2 catalyst prepared by the conventional method is as high as 300 °C. Notably, the 5-MI-500 catalyst exhibits the highest proportion of well-dispersed CuO and Cu-O-Ce structures, which synergistically enhance catalyst activity. The well-dispersed CuO particles enhance the redox ability of the catalyst, while the Cu-O-Ce structure provides high activated oxygen via oxygen vacancy and better thermal stability during catalytic reaction. Accordingly, the possible reaction mechanism over the 5-MI-500 catalyst for EA oxidation was proposed. This study demonstrates that the MI method reported in this paper can provide a feasible methodology to prepare highly active catalysts with unique structures.

Pt-decorated ZnFe2O4 sensors prepared via a facile impregnation method free of reductants and surfactants for conductometric acetone sensing

Noble metals have been widely reported to improve sensing properties. However, conventional methods of preparing noble metal-decorated metal oxide sensors usually involve the use of multiple reductants and surfactants, as well as complex equipment and procedures, and most importantly, waste noble metal sources. In this study, we develop a novel modified impregnation method, which is a green, energy-saving, fast, convenient technique for preparing Pt-decorated ZnFe2O4 gas sensors. This method consists only of mixing ZnFe2O4 powder into a H2PtCl6 solution and then fabricating sensors by a general procedure, without the use of additional reagents or further treatment. Detailed structural and chemical analyses revealed that over 88% of Pt element was uniformly dispersed on the surface of ZnFe2O4. The average activation energy decreased by 51% after Pt was decorated onto the surface of ZnFe2O4, resulting in a shorter response time. As expected, the thus prepared Pt-decorated ZnFe2O4 sensors are superior to pristine commercial ZnFe2O4 in terms of better sensing properties, a higher response, and a lower optimal temperature. The proposed reductant-free impregnation method was demonstrated to provide noble-metal-decorated metal oxides successfully, easily, quickly, and economically.

Advances in Enhancing the Stability of Cu-Based Catalysts for Methanol Reforming

The advent of fuel cells has led to a series of studies on hydrogen production. As an excellent hydrogen carrier, methanol can be used for reforming to produce hydrogen. Copper-based catalysts have been widely used in methanol reforming due to their high catalytic activity and low-cost preparation. However, copper-based catalysts have been subjected to poor stability due to spontaneous combustion, sintering, and deactivation. Thus, the research on the optimization of copper-based catalysts is of great significance. This review analyzes several major factors that affect the stability of copper-based catalysts, and then comments on the progress made in recent years to improve the catalytic stability through various methods, such as developing preparation methods, adding promoters, and optimizing supports. A large number of studies have shown that sintering and carbon deposition are the main reasons for the deactivation of copper-based catalysts. It was found that the catalysts prepared by the modified impregnation method exhibit higher catalytic activity and stability. For the promoters and supports, it was also found that the doping of metal oxides such as MgO and bimetallic oxides such as CeO2-ZrO2 as the support could present better catalytic performance for the methanol reforming reaction. It is of great significance to discover some new materials, such as copper-based spinel oxide, with a sustained-release catalytic mechanism for enhancing the stability of Cu-based catalysts. However, the interaction mechanism between the metal and the support is not fully understood, and the research of some new material copper-based catalysts in methanol reforming has not been fully studied. These are the problems to be solved in the future.

An efficient photocatalytic system under visible light: In-situ growth cocatalyst Ni2P on the surface of CdS

Cocatalyst contributes to promote the separation and transfer of charge in photocatalytic system, which is an important factor to improve photocatalytic decomposition of water to produce hydrogen. Here, a simple and effective method to combine the main catalyst and the cocatalyst by a modified impregnation method is provided. A novel Ni2P/CdS is prepared by in-situ growth of Ni2P cocatalyst on the CdS surface using the modified impregnation method. The research shows that Ni2P, as an electron carrier, can promote the separation of electrons and holes, and significantly improve the photocatalytic activity of Ni2P/CdS. When Ni2P was 3% in Ni2P/CdS, the photocatalytic activity of hydrogen production was the highest, and the hydrogen production rate reached an astonishing 16.02 mmol h−1g−1 under visible light, which was 57 times that of CdS. Moreover, Ni2P/CdS photocatalyst has outstanding stability for hydrogen production. The mechanism of photocatalytic hydrogen production by Ni2P/CdS is proposed.

Characterization of Various MnOx Doped CSAC and Its Application for Efficient Catalysis of Hydrogen Peroxide

In the present work, the experiments of catalytic decomposition of hydrogen peroxide (H2O2) were carried out by using a series of prepared catalysts doped the coconut shell activated carbon (CSAC) under Fenton-like system. The relevant catalysts were prepared by the modified impregnation method. The effects of various catalysts had also been studied in the reaction system. The rate of catalytic decomposition of H2O2 was measured at regular time intervals. Besides, the optimum catalysts were characterized by SEM, EDX, BET, and XRD instruments. And it was demonstrated that the rich Mn3O4 and K2-xMn8O16 were beneficial for the catalytic activity, which may account for its superior catalytic efficiency.

Photocatalytic degradation of methylene blue with spent FCC catalyst loaded with ferric oxide and titanium dioxide

The spent fluid catalytic cracking (FCC) catalyst has been loaded with ferric oxide (Fe2O3) and titanium dioxide (TiO2). Fe-Ti/SF composite (loaded with 5 wt% TiO2 and 5 wt% Fe2O3), Fe/SF composite (loaded with10 wt% Fe2O3) and Ti/SF composite (loaded with 10 wt% TiO2) have been fabricated via a modified-impregnation method. The band gaps of the Fe-Ti/SF, Fe/SF and Ti/SF composites (evaluated by the energy versus [F(R∞)hv]n) are 2.23, 1.98 and 3.0 eV, respectively. Electrochemical impedance spectroscopy shows that the Fe-Ti/SF has lower electron transfer resistance, it has the small charge transfer resistance and fast charge transfer rate. The interparticle electrons transfer between the Fe2O3 and TiO2, which can improve the separation of the photo-electrons and holes. The holes transfer from valence band of TiO2 to the valence band of Fe2O3, which can provide more active sites around the adsorbed molecules. The methylene blue degradation efficiencies (with the Fe-Ti/SF, Fe/SF and Ti/SF composites) are ~ 94.2%, ~ 22.3% and ~ 54.0% in 120 min, respectively. This work reveals that the spent FCC catalyst as supporter can be loaded with Fe2O3 and TiO2. This composite is highly suitable for degradation of methylene blue, which can provide a potential method to dispose the spent FCC catalyst in industry.

Effect of support acidity during selective hydrogenolysis of glycerol over supported palladium-ruthenium catalysts.

We report the role of the acidity of support during the selectivity hydrogenolysis of glycerol over supported bimetallic palladium-ruthenium (PdRu) catalysts. The PdRu nanoparticles were supported on a series of metal oxides and zeolitic supports via the modified impregnation method and tested for the liquid-phase hydrogenolysis of glycerol using gaseous hydrogen. The relative acid site densities of selected catalysts were determined by ammonia temperature-programmed desorption and pyridine desorption experiments. Based on these studies, we report a direct correlation between the catalytic activity (conversion and 1,2 propane diol yield) and two different acid sites (strong acid sites and very strong acid sites). Besides zeolite-supported catalysts, TiO2 supported PdRu nanoparticles exhibit moderate catalytic activity; however, this catalyst shows high selectivity for the desired C-O bond cleavage to produce C3 products over the undesired C-C bond cleavage to produce < C3 products. This article is part of a discussion meeting issue 'Science to enable the circular economy'.

Synergetic Bimetallic NiCo/CNT Catalyst for Hydrogen Production by Glycerol Steam Reforming: Effects of Metal Species Distribution

Bimetallic catalysts NiCo/CNTs with distribution-controlled Ni and Co species were prepared by modified impregnation method with the assistance of dimethylbenzene and characterized by XRD, N2 adsor...

Application of magnetic alumina-ferric oxide nanocatalyst supported by KOH for in-situ transesterification of microalgae cultivated in wastewater medium

Nowadays, use of microalgae as a cheap feedstock and heterogeneous catalysts for biodiesel production has gained considerable interest as they mitigate environmental problems induced by the conventional process of biodiesel production using homogeneous alkali catalysts. However, separation of heterogeneous catalysts from tissues and carcass of microalgae is an important task. For this reason, a magnetic Fe2O3–Al2O3 nanocatalyst promoted by potassium groups was synthesized using a modified impregnation method and was profoundly studied and compared with nanocatalysts without ferric oxide using X-ray diffraction, Fourier-transform infrared, Brunauer-Emmett-Teller and Barrett-Joyner-Halenda, scanning electron microscopy, transmission electron microscopy and energy-dispersive spectroscopy analyses. The results revealed that the magnetic nanocatalyst with a core-shell structure had suitable surface area, pore size, and particle size and also had no impurity on its structure. The nanocatalyst was used for biodiesel production from microalgae cultivated in a wastewater medium via in-situ transesterification reaction. The nanocatalyst converted 95.6% of microalgae lipids to esters at optimum conditions of 65 °C, 12 mL g−1 of methanol-to-dry biomass, 4 wt% of magnetic catalyst and 6 h of reaction time. The magnetic K/Fe2O3–Al2O3 core-shell nanocatalyst was reused for several times and presented high stability with less reduction in its activity until six runs.

Fabrication of spent FCC catalyst composites by loaded V2O5 and TiO2 and their comparative photocatalytic activities

The spent fluid catalytic cracking catalyst (FCC) has been loaded with different content of V2O5 and TiO2 through a modified-impregnation method. X-ray Diffraction (XRD), ultraviolet-visible spectrophotometry (UV-Vis), Scanning Electron Microscope (SEM), and Fourier Transform Infrared spectroscopy (FT-IR) are used to characterize the structure and morphology of these samples. Their photocatalytic activity was evaluated by degradation of methylene blue (MB) solution under 300 W Xenon lamp irradiation. The interplanar spacing of the zeolite Y (111) plane is affected by the amount of the loaded V2O5 on spent FCC catalyst. The (111) plane of spent FCC catalyst loaded with V2O5 and TiO2 sample is 1.404 nm, which is higher than that of the zeolite Y (1.395 nm). The amount of adsorption of MB and the photocatalytic activity for the degradation increased with increasing the interplanar spacing of the (111) plane of sample. We fabricated of spent FCC catalyst composites by loaded V2O5 and TiO2, which effectively solved the spent FCC catalyst disposal problem. The efficiency of the developed sample provides a potentially economical way of degrading MB.

Thermal stability of oxide-supported gold nanoparticles

In this study, we report on the influence of support and gas atmosphere on the thermal stability of Au nanoparticles on oxidic supports. All samples were prepared with a modified impregnation method and have initial Au particle sizes in the range of 3–4 nm. We observed that in air, Au nanoparticles on SiO2 and Al2O3 are thermally much more stable than Au nanoparticles on TiO2. For instance, upon treatment up to 700 °C, on SiO2, Au particles grew from 4 to 6 nm while on TiO2 from 3 to 13 nm. For Au nanoparticles on TiO2, growth is accelerated by oxidizing atmospheres and the presence of water and/or chloride. On non-reducible supports and in non-oxidizing atmosphere, the supported Au nanoparticles were remarkably stable. The insight into the growth of oxide-supported Au nanoparticles in reactive atmosphere offers an additional tool for a rational choice of a support for high-temperature gas-phase reactions involving gold nanocatalysts.

Development of New Electrocatalytic Nanomaterials for the Oxidation of Ammonia As Anodic Materials in a Direct Ammonia Fuel Cell

Fuel cells are electrochemical devices that directly convert chemical energy to electrical energy. A common justification for using fuel cells has been environmental protection, as fuel cells produce only water as combustion by-product and thus they are “zero emission” devices [1]. The most widely deployed fuel cell is PEMFC, which uses hydrogen as fuel. However, fuel distribution and fuel tank fill-up, associated with the physical state of the fuel, a highly compressed gas, is problematic. In order to achieve the effective energy content of a gasoline tank, an H2 pressure of 700 bar is required in FCV's storage tanks. An alternative approach to avoid using compressed hydrogen, is to use liquid hydrogen-rich fuels such as methanol, ethanol or ammonia, which are liquid in conditions close to the atmosphere. Being liquid fuels, they are easy to transport and store, which reduces transport and infrastructure costs. In addition, it allows by minor modifications, to take advantage of the current infrastructure and facilities that are normally used for conventional fuels.Recently hydrogen carriers have attracted much attention as alternative fuels to hydrogen for the realization of a low-carbon society. The search for a clean, economical and sustainable fuel with high energy density has led to the increasing consideration of nitrogen-based fuels, such as ammonia and hydrazine, as a promising alternative reactant to use in fuel cells. Ammonia has certain advantages over other N2-compounds. It is extensively used in the agricultural, plastics and explosives industries. In addition, ammonia is produced on an industrial scale by the well-known Haber-Bosch method. There are many other advantages to consider ammonia, as a promising candidate among them liquefaction under mild conditions (−33.4 °C at atmospheric pressure or 8.46 atm at 20 °C), high volumetric energy density, low production cost, and being a carbon-free fuel. In response to these technical trends, the development of energy conversion devices utilizing ammonia fuel such as fuel cells and gas turbine generators has now accelerated [2].Electrochemical oxidation of ammonia attracted great attention for wastewater treatment, as well as its application in direct ammonia fuel cells and hydrogen production in energy conversion technologies. However, ammonia electro-oxidation to produce H2 and N2 is a slow process and efficient electrocatalysts are required [3]. Several studies have been devoted to the development of efficient electrocatalysts for ammonia oxidation in alkaline solutions. Platinum is the most active catalyst for this process, however it is expensive and easily become inactive by nitrogen adsorption. Various mono- and bimetallic catalysts have been investigated [4]. In order to make ammonia FCs commercially attractive, the amount of precious metals needs to be reduced. This can be achieved by using electrocatalysts as nanoparticles dispersed on high surface area conductive supports, e.g., carbon black. In this work carbon-supported bimetallic, PtM, as well as trimetallic PtMRu (M = Co, Cu, Ru, Ni) catalysts were synthesized using a modified impregnation method [5]. These synthesized materials have been studied as potential catalysts for ammonia electro-oxidation. All materials were characterized physic chemically by techniques such as TEM, SEM, EDS and XPS. in order to determine the size and distribution of the nanoparticles on the conductive support and the chemical composition and oxidation state of the constituent elements of the catalyst. Techniques such as CV, CA and EIS were used for electrochemical characterization. All electrochemical measurements were carried out in a three-electrode PTFE homemade cell. A large surface area gauze-Pt and a Ag/AgCl electrode were used as the counter electrode and the reference electrode, respectively. As working electrode a glassy carbon with a thin catalyst layer was used. The behaviour of the new materials towards ammonia electrooxidation was evaluated. 1 M KOH was used as the supporting electrolyte, to which increasing amounts of NH4OH were added. The catalysts synthesized in this work have shown to be very attractive as active materials for the anode of a direct ammonia fuel cell. The addition of co-catalysts to the Pt has improved its electrocatalytic behavior towards ammonia electro-oxidation. [1] Frontiers of Engineering: Reports on Leading-Edge Engineering from the 2005 Symposium. (2006). Washington, D.C.: National Academies Press. [2] Matsui, T., Suzuki, S., Katayama, Y., Yamauchi, K., Okanishi, T., Muroyama, H., & Eguchi, K. (2015). Langmuir, 31(42), 11717–11723. [3] Siddiqui, O., & Dincer, I. (2018). Thermal Science and Engineering Progress, 5, 568-578. [4] Lomocso, T. L., & Baranova, E. A. (2011). Electrochimica Acta, 56(24), 8551–8558. [5] Asteazaran, M., Cespedes, G., Moreno, M. S., Bengió, S., & Castro Luna, A. M. (2015). International Journal of Hydrogen Energy, 40(42), 14632–14639.

Benzyl alcohol oxidation with Pd-Zn/TiO2: computational and experimental studies

ABSTRACT Pd–Zn/TiO2 catalysts containing 1 wt% total metal loading, but with different Pd to Zn ratios, were prepared using a modified impregnation method and tested in the solvent-free aerobic oxidation of benzyl alcohol. The catalyst with the higher Pd content exhibited an enhanced activity for benzyl alcohol oxidation. However, the selectivity to benzaldehyde was significantly improved with increasing presence of Zn. The effect of reduction temperature on catalyst activity was investigated for the catalyst having a Pd to Zn metal molar ratio of 9:1. It was found that lower reduction temperature leads to the formation of PdZn nanoparticles with a wide particle size distribution. In contrast, smaller PdZn particles were formed upon catalyst reduction at higher temperatures. Computational studies were performed to compare the adsorption energies of benzyl alcohol and the reaction products (benzaldehyde and toluene) on PdZn surfaces to understand the oxidation mechanism and further explain the correlation between the catalyst composition and its activity.

Improved structural stability and catalytic performance for CH4 reforming reaction of mesoporous MCM-41 analogs prepared by zeolitic subunits of MOR desilication

We demonstrated a new strategy for the preparation of highly stable mesoporous molecular sieves (TMM) by the desilication of MOR zeolite and self-assembling of the zeolite subunits in Na2O•(3.3–3.4) SiO2 aqueous solution. Na2O•(3.3–3.4) SiO2 in the aqueous solution plays two roles in the synthesis, one was providing a moderate alkaline medium with buffering effect for the desilication of MOR zeolite, other one was supplementing silica source. The desilication conduction of MOR zeolite was optimized by the adjustment of reaction temperature and time, pH in the solution. TMM were characterized by X-ray diffraction (XRD), N2 adsorption/desorption (BET), Fourier transformed infrared (FT-IR) and transmission electron microscopy (TEM). The characterization results showed that the characteristics of MOR zeolite, such as double six-membered or five-membered ring subunits, were still preserved in TMM, and TMM possessed well-ordered mesostructure of MOR zeolite crystals. Compared with the pure silica mesoporous molecular sieve (MCM-41, 4-day), the hydrothermal stability of TMM (17-day) was increased by 100% with refluxed water. The significantly improving of TMM hydrothermal stability was due to increase the surface hydrophobicity and the ratio of T12-ring, and decreased remarkably number of hydrophilic silanol groups. After hydrothermal treatment for 17-day, TMM also exhibited more efficient catalytic activation than MCM-41 treated for 4-day in CO2 reforming of methane reaction (700 °C). The 5 wt% Ni/TMM-17d-Glu (5 wt% Ni, loading) catalysts prepared by Glucose modified impregnation method exhibited excellent catalytic activity, which were providing 58% CO2 and 47% CH4 conversions at 700 °C.

Performance of the ZrO2 promoted Cu[sbnd]ZnO catalyst supported on acetic acid-treated MCM-41 in methanol steam reforming

ZrO2-promoted CuZnO catalysts were prepared through the sol-gel, conventional impregnation and modified impregnation methods using MCM-41 as support material and applied to the methanol steam reforming (MSR) reaction. The synthesized catalysts were characterized by the XRD, BET, FESEM, TEM, XRF, FTIR, H2-TPR and TGA methods. The determined physiochemical properties suggested that pretreatment of MCM-41 with acetic acid before metal impregnation remarkably decreases the size of the metal particles and improves their dispersion and reduction behavior. Among the synthesized catalysts, the CuZnOZrO2/MCM-41 sample prepared through the modified impregnation method exhibited the best catalytic performance with 97.8% methanol conversion, 99.0% H2 selectivity, 0.4% CO selectivity and the lowest level of coke deposition, at 300 °C. In addition, all catalysts resisted against deactivation by conserving their catalytic activity over 40 h operation, indicating that the use of high surface area MCM-41 as support, the ZrO2 promoter, and the proper synthesis methods significantly enhanced the catalytic activity in the MSR process.

Synthesis, characterization, and application of easily accessible resin-encapsulated nickel nanocatalyst for efficient reduction of functionalized nitroarenes under mild conditions

A novel resin-encapsulated nickel nanocatalyst has been synthesized by a modified impregnation method using nickel acetate tetrahydrate in presence of sodium borohydride as a mild reducing agent. The synthesized nanocatalyst was characterized by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The concentration of nickel nanoparticles encapsulated on resin was determined by inductively coupled plasma-mass spectroscopy (ICP-MS). Further, synthesized resin-encapsulated nickel nanocatalyst was found to be stable and efficient in micromolar concentrations, for the selective reduction of functionalized nitroarenes to corresponding amines in good to high yield, under mild reaction conditions. The nanocatalyst shows excellent reusability. SYNOPSIS A novel resin-encapsulated nickel nanocatalyst (Ni@XAD-4) was synthesized using a modified impregnation method. The nanocatalyst exhibited excellent catalytic activity towards the selective reduction of functionalized nitroarenes in the presence of $$\hbox {NaBH}_{4}$$ with reusability up to five cycles.

Enhanced activity of Ni/SiO2 catalyst in dry reforming of CH4 via a modified impregnation method

A modified impregnation method with the addition of NH4NO3 was employed to prepared the supported Ni catalyst (denoted as Ni/SiO2-N). And the obtained catalyst exhibited an improved catalytic activity and stability in DRM at 800°C with GHSV of 48 L⋅gcat.−1⋅h−1 and CH4/CO2/N2 = 9/9/2. The XRD and H2-TPR results showed that the Ni/SiO2-N catalyst was possessed with smaller Ni particles and stronger metal-support interaction than Ni/SiO2 catalyst prepared by the common impregnation method, leading to the better catalytic performance. It is the decomposition of NH4NO3 which can generate extra heat in a short time during the catalyst preparation process that make the change in structure and performance of catalyst.

Atmospheric-Pressure Cold Plasma Activating Au/P25 for CO Oxidation: Effect of Working Gas.

Commercial TiO2 (P25) supported gold (Au/P25) attracts increasing attention. In this work, atmospheric-pressure (AP) cold plasma was employed to activate the Au/P25-As catalyst prepared by a modified impregnation method. The influence of cold plasma working gas (oxygen, argon, hydrogen, and air) on the structure and performance of the obtained Au/P25 catalysts was investigated. X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), and X-ray spectroscopy (XPS) were adopted to characterize the Au/P25 catalysts. CO oxidation was used as model reaction probe to test the Au/P25 catalyst. XRD results reveal that supporting gold and AP cold plasma activation have little effect on the P25 support. CO oxidation activity over the Au/P25 catalysts follows the order: Au/P25-O2P > Au/P25-As > Au/P25-ArP ≈ Au/P25-H2P > Au/P25-AirP. Au/P25-AirP presents the poorest CO oxidation catalytic activity among the Au/P25 catalysts, which may be ascribed to the larger size of gold nanoparticles, low concentration of active [O]s, as well as the poisoning [NOx]s. The poor catalytic performance of Au/P25-ArP and Au/P25-H2P is ascribed to the lower concentration of [O]s species. 100% CO conversion temperatures for Au/P25-O2P is 40 °C, which is 30 °C lower than that over the as-prepared Au/P25-As catalyst. The excellent CO oxidation activity over Au/P25-O2P is mainly attributed to the efficient decomposition of gold precursor species, small size of gold nanoparticles, and the high concentration of [O]s species.