Deposition Of CeO2 Research Articles

Enhanced thermal performance of CeYSZ coating on Ni-based high temperature alloy with a unique Y-doped Al2O3 barrier layer via cathodic plasma electrolytic deposition

Cathodic plasma electrolytic deposition (CPED) has shown considerable potential in producing high-performance thermal barrier coatings (TBCs) for components operating in extreme thermal environments, such as gas turbines and aviation engines. However, the dendritic and porous structures greatly limited the use of CPED-coatings in some harsh environments. In this study, one Y-doped Al2O3 (Y/A) barrier layer was prefabricated before the deposition of CeO2 and Y2O3 stabilized ZrO2 (CeYSZ) TBCs using CPED. The results suggested that the prefabricated Y/A barrier layer could attenuate the plasma bombardment and promote the uniform discharge, resulting in the formation of a thinner gas film on the cathode surface, which significantly avoided the dendritic defects and improved the density of the CeYSZ coating from 6.788 g/cm³ to 6.978 g/cm³. Consequently, the thermal insulation temperature of Y/A-CeYSZ coatings increased by 83.7% than that of CeYSZ coating, and the thermal cycling performance at 1300 °C demonstrated a 52.5 % improvement. This study provided a valuable method for the development of novel CPED TBCs.

Probing Pt-CeO2 interfacial interactions through adsorption characteristics of small molecules

In this study, we prepared a Pt/CeO2/Cu(111) model catalyst and investigated CO and CO2 adsorption using infrared reflection absorption spectroscopy (IRRAS) and temperature-programmed desorption (TPD) techniques to gain insight into the interaction between Pt nanoparticles and the CeO2 support surface. Our observations revealed that the deposition of CeO2 at 700 K results in island formation on the Cu(111) surface, whereas at 520 K it leads to a more continuous film formation. Reducing the CeO2/Cu(111) surface enhances the CO and CO2 uptakes on CeO2. Pt nanoparticles deposited on these surfaces remained in a metallic form, and during CO desorption, they facilitate the oxidation of CO to form CO2 by utilizing lattice oxygen from the interface between them and CeO2.

Susceptibility of Poly–Alpha Olefin and Diisooctyl Sebacate Base Oils With Different Polarities to Oleic Acid Surface–Capped Ultra‐Small Cerium Oxide Nanoparticle

ABSTRACTA key issue for nano‐additive to effectively exert tribological function is to ensure its entrance to and adhesion on the frictional contact surfaces. But the adhesion of nano‐additive on the rubbed surfaces under oil lubrication faces the challenge of the competitive adsorption of lubricant base oil thereon. In this study, oleic acid–modified ultra‐small cerium oxide (OA‐CeO2) nanoparticle was synthesised by one‐pot liquid‐phase surface‐modification method in the presence of OA as the surface modifier. The susceptibility of non‐polar poly–alpha olefin 6 (PAO6) and polar diisooctyl sebacate (DIOS) base oils to the as‐prepared OA‐CeO2 nano‐additive was investigated, and the effect of the OA‐CeO2 nano‐additive on the friction‐reducing and anti‐wear abilities of the two kinds of base oils towards a steel–steel sliding contact was investigated with four‐ball friction and wear tester. Furthermore, the tribological mechanism of the adsorption and deposition of the OA‐CeO2 nano‐additive on the surface of friction steel and the competitive adsorption of base oil were discussed. Characterisations by scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy demonstrate that the as‐prepared OA‐CeO2 nanoparticle is of a spherical shape and has an ultra‐small average size of 1.2 nm. As the lubricant additive in PAO6 and DIOS base oils, the OA‐CeO2 nano‐additive exhibits different tribological properties, which is attributed to the difference in the base oils' polarity. Namely, the CeO2 nanoparticle in the non‐polar PAO6 base oil is more easily adsorbed on the rubbed surface of the steel–steel sliding contact, thereby forming the CeO2 deposition film to improve the tribological properties of the base oil. However, the CeO2 nanoparticle added in polar DIOS base oil is difficult to form the CeO2 deposition film, because of the competitive and preferential adsorption of the polar base oil on the rubbed steel surface. Therefore, it is imperative to select the base oils with proper polarity to better exert the friction‐reducing and anti‐wear functions of the OA‐CeO2 nano‐additive.

Solar photothermo-catalytic conversion of CO2 on phyllosilicates modified with Ni and CeO2

One of the strategies to mitigate the greenhouse effect is converting the CO2 into high-added value products. In this work, a photothermo-catalytic approach, using peculiar Ni-phyllosilicates samples, was applied for the CO2 conversion into solar fuels. In particular, the Ni-phyllosilicates were modified with the introduction of the Ce ions in their structure and successively they were covered with the CeO2 semiconductor. The structural, morphological, textural, optical and reducibility properties as well as the interaction with CO2 were investigated. The Ni/Ce-phyllosilicate covered with CeO2 achieved a CO2 conversion of 87% after 5 hours of photothermo-catalytic test using simulated solar irradiation at 120°C, producing 15.8 μmol/gcat∙h of CO and 5.6 μmol/gcat∙h of CH4. The same sample was tested in an integrated approach where the CO2 was evolved by the catalytic oxidation of toluene and then was converted into CO and CH4, obtaining a CO2 conversion of 50% and 8.8 μmolCO/gcat∙h and 3.3 μmolCH4/gcat∙h. The presence of Ni in the phyllosilicates structure guaranteed a good catalytic stability whereas the deposition of CeO2 allowed to exploit the improved thermal (redox) properties of cerium oxide and favoured the CO2 adsorption on its basic sites and oxygen vacancies. Furthermore, the high surface area of the as-synthetized Ni-phyllosilicates permitted to efficiently expose the CeO2 surface-active sites to the solar radiation. The here investigated catalysts showed versatile properties ideal for hybrid catalytic approaches as the photothermo-catalysis, allowing to propose new solutions for the CO2 valorization.

Vapor deposited CeO2 nanostructures by atmospheric plasma spray with reversible wettability

The construction of nanostructures on the coating surface by vapor deposition of CeO2 was realized during atmospheric plasma spraying (APS). The backside deposition method was specially designed to demonstrate the occurrence of vapor deposition and to collect pure vapor-deposited nanostructures for performance development. The effects of high-temperature and high-speed deposition conditions, the intrinsic high vapor pressure of CeO2, and the agglomerated porous feature of the powder on the formation of vapor phase were discussed and the deposition mechanism was revealed. The study developed the reversible wettability of vapor-deposited nanostructures under vacuum and UV-O3 alternate treatment.

Remarkably efficient Pt/CeO2–Al2O3 catalyst for catalytic hydrodeiodination of monoiodoacetic acid: Synergistic effect of Al2O3 and CeO2

Monoiodoacetic acid (MIAA) is one of the highly toxic halogenated disinfection by-products, which is formed during water disinfection processes. Catalytic hydrogenation with supported noble metal catalyst is a green and effective technique for the transformation of halogenated pollutant, but its activity still needs to be identified. In this study, Pt nanoparticles were supported on CeO2 modified γ-Al2O3 (Pt/CeO2–Al2O3) by chemical deposition method and the synergistic effect of Al2O3 and CeO2 on catalytic hydrodeiodination (HDI) of MIAA was systematically studied. Characterizations revealed that Pt dispersion could be improved by the introduced CeO2 through the formation of Ce–O–Pt bond and MIAA adsorption could be facilitated by high Zeta potential of Al2O3 component. Furthermore, optimal Ptn+/Pt0 could be obtained by adjusting CeO2 deposition amount on Al2O3, which could effectively facilitate the activation of C–I bond. Therefore, Pt/CeO2–Al2O3 exhibited remarkable catalytic activities and TOF values compared with those of Pt/CeO2 and Pt/Al2O3. Through detailed kinetic experiments and characterization, the extraordinary catalytic performance of Pt/CeO2–Al2O3 can be attributed to the abundant Pt sites as well as the synergistic effect between CeO2 and Al2O3.

Deposition of CeO2 on TiO2 nanorods electrode by dielectric barrier discharge plasma to enhance the photoelectrochemical performance in high chloride salt system

• One-step deposition and synthesis of CeO 2 /TiO 2 -NRs electrode by DBD plasma. • A bond combined CeO 2 (1 1 1) with TiO 2 was formed in CeO 2 /TiO 2 -NRs electrode. • The proportion of Ce 3+ /Ce 4+ was increased by plasma modification to enhance oxygen vacancy. • Heterojunction was formed between TiO 2 and CeO 2 to have a narrower band gap. • DBD plasma promotes PEC performance of CeO 2 /TiO 2 -NRs in high chloride salt system. In this study, cerium oxide (CeO 2 ) was deposited on TiO 2 nanorods (TiO 2 -NRs) through the one-step deposition by using dielectric barrier discharge (DBD) plasma treatment, where this was a simple and efficient means of synthesizing a CeO 2 /TiO 2 -NR electrode. The results of X-ray diffraction indicated that CeO 2 (1 1 1) was successfully loaded on the TiO 2 -NRs, and the peak shifted in the positive direction after DBD discharge-induced modification, indicating that a bond between CeO 2 and TiO 2 had been formed in the CeO 2 /TiO 2 -NR electrode. Based on X-ray photoelectron spectroscopy, the ratio of Ce 3+ /Ce 4+ increased due to plasma modification to enhance the oxygen vacancy of the CeO 2 /TiO 2 -NRs in the lattice structure. The CeO 2 /TiO 2 -NR composite electrode delivered the best photoelectrochemical (PEC) performance at a modified input voltage of 45 V and a deposition time of 10 min due to DBD discharge. The efficiency of removal of phenol from simulated seawater with a high salt system yielded the highest value of 97.1% for the CeO 2 /TiO 2 -NR electrodes through the PEC process at 3 V and UV–visible irradiation. A mechanism of the PEC performance of the CeO 2 /TiO 2 -NRs electrode was proposed, whereby a heterojunction was formed between TiO 2 and CeO 2 to increase the effect of oxygen storage, and active chlorine ions were produced in the high chloride salt system to enhance the degradation of pollutants.

Evaluation of alkoxide β-diketonates Ce(III), Er(III), Ln(III) complexes as precursors for the photo-deposition of CeO2:Er/Ln amorphous thin films and their influence on the luminescent properties (where Ln = Pr or Yb)

We propose the use of alkoxide β-diketonates of Ce(III), Er(III), Pr(III) and Yb(III) as precursors for photochemical deposition of CeO2:Er and CeO2:Er/Ln (Ln = Pr or Yb) thin films, followed by subsequent annealing at 950 °C. The measurements of luminescent properties revealed that CeO2:Er samples under excitation at 980 nm exhibit up-conversion emissions at 540 nm and near infrared emissions centered at 1550 nm. When co-doping is performed on the CeO2 films, CeO2:Er/Pr reduces its up-conversion characteristics and the NIR emissions increase. However, the CeO2:Er/Yb samples significantly increase the up-conversion properties and inhibit NIR emissions. Different mechanisms based on energy transfer processes are proposed to explain these differences in the degree of intensity of these emissions.

Preparation and Properties of Modified Graphene Reinforced Aluminum Matrix Composites

In order to solve the problem of agglomeration of graphene in preparation of composites, GN-CeO2 powders with even dispersion were obtained by a hydrothermal reduction method, which involved modifying the surface of acidified graphene by cerium nitrate. Then, Al/GN-CeO2 composite powders and materials were prepared by high-energy ball milling and vacuum hot pressing, respectively. The details were investigated, including the effect of modification process on the surface morphology and functional groups of graphene and modification time on the properties of Al/GN-CeO2 composites. The result shows that the functional groups and defects of graphene were added by the treatment of acidification process, which is beneficial to the composite of graphene and CeO2 particles. The quantity of CeO2 deposition on graphene surface increased with the duration of hydrothermal reduction time. After 6 h modification, the properties of the composites performed best. Compared with Al/GN composites, the tensile strength of the modified composites was increased from 284 MPa to 321 MPa; and the tensile strain rate of the modified composites was increased to 12.3%；the hardness of the modified composites was increased from 97.1 Hv to 99.5 Hv；the conductivity of the modified composites was increased from 29.84%IACS to 33.21%IACS.

Crystallographic Characterization of a CeO2 Protective Layer Deposited on a Ni–Cr Anode for Molten Carbonate Fuel Cell

A Ni–Cr anode, dip coated with Ce oxide for increasing the resistance to sulfur poisoning of high-temperature molten carbonate fuel cell, has been investigated by neutron diffraction. Crystallographic characterization of the phases present in this anode has been obtained by Rietveld refinement. In the substrate Ni–Cr is detected, with Fm $$\bar {3}$$ m structure and weight volume fraction of 68.50(46) wt %. Additionally, due to oxidation during coating also NiO is present (space group Fm $$\bar {3}$$ m), with weight volume fraction of 25.28(18) wt %. The thin protective layer consists of nanostructured CeO2 (Fm $$\bar {3}$$ m), with an estimated massive volume fraction of 6.3(5) wt %. These results support the effectiveness of the adopted CeO2 deposition procedure and show the usefulness of neutron diffraction also for investigating thin protective layers.

Effect of cerium oxide doping on the photocatalytic properties of rutile TiO2 films prepared by spray pyrolysis

The spray pyrolysis is fast and simple method for deposition of CeO2 – rutile TiO2 coatings on stainless steel substrate. The coatings were deposited on stainless steel substrate and characterized by XRD, AFM, XPS, Raman, DRS and photoactivity test for methyl orange decolorization. Photoactivity of CeO2 – rutile TiO2 coatings increase with increasing CeO2 content up to 5 wt% and further increase of CeO2 content leads to decrease of photoactivity. Improvements of photoactivity originate from close contact between CeO2 and rutile TiO2 particles which create numerous centers able to produce very reactive radical species. Besides, the close contact between the CeO2 and rutile TiO2 provides easier charge transfer facilitating the formation of electron/hole pairs that is a necessary step in the overall photocatalytic process.

DFT Study on Atomic Layer Deposition of Cerium Dioxide on Hydroxylated Titanium Dioxide As Efficient Photocatalyst

Design of photocatalyst materials for hydrogen production is of great interest due to a lack of cost-effective candidates. Titanium dioxide (TiO2) is a well-known photocatalyst with good stability, reasonable photoactivity, and low cost. To improve the efficiency and selectivity, we apply a surface modification approaches using nanostructured Cerium dioxide (CeO2) deposited onto TiO2 by atomic layer deposition (ALD). The deposition of CeO2 onto TiO2 uses the precursor Tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionato)cerium (IV) (Ce(TMHD)4) and co-reactant ozone.The atomic layer deposition (ALD) of CeO2 on TiO2 was carried out by experiments with an atmospheric pressure fluidized bed ALD reactor. The TiO2 substrate was pre-treated using a combination of ozone and humidified nitrogen flow pulses to investigate the effect of the increase of surface functional groups on CeO2 deposition. The physicochemical properties of the obtained CeO2/TiO2 photocatalysts were characterized using different methods and their photocatalytic activity was evaluated during photocatalytic hydrogen evolution reaction.We have also performed density functional theory (DFT) calculations to investigate the reaction mechanism of metal precursors Ce(TMHD)4 and tris(methylcyclopentadienyl)cerium (III) (Ce(MeCp)3) on hydroxylated rutile and anatase TiO2 surfaces. The hydroxyl saturation coverage on different TiO2 facets was first addressed. These facets include anatase a-TiO2(001) and a-TiO2(101) and rutile r-TiO2(100) and r-TiO2(110). Hydroxyl groups OH and H are initially binding to surface Ti and O atoms, respectively. On a-TiO2(001) hydroxyl recombination to form water results in a final coverage of 0.81ML, due to the shortest neighboring HO-H distance on all surfaces. The Gibbs energy is then calculated to elucidate the effect of pressure and temperature on the hydroxylated termination of TiO2 surfaces. The final hydroxyl coverage is as follows: 0.81ML on a-TiO2(001) surface, 1ML on a-TiO2(101) and r-TiO2(100) surfaces, and 0.75ML on r-TiO2(110) surface.Two precursors (Ce(TMHD)4 and Ce(MeCp)3) are adsorbed on hydroxylated TiO2 surfaces. After precursor adsorption and relaxation, the surface hydroxyl coverage changes with water formation. After Ce(THMD)4 adsorbed on r-TiO2(100) surface, the hydroxyl coverage is decreased from 1ML to 0.25ML with 12 H2O molecules formation. After Ce(MeCp)3 adsorbed on a-TiO2(101) surface, although the hydroxyl coverage is not changed, the hydroxyl orientation is modified, breaking the symmetry. For Ce(TMHD)4, direct ligand dissociation is applied to study the mechanism of eliminating the ligands. For Ce(MeCp)3, the ligand can be eliminated by hydrogen transfer. The barrier for hydrogen transfer is calculated using climbing image nudged elastic band (CI-NEB) method. The results show that for Ce(MeCp)3, the reaction is endothermic on a-TiO2(101) surface, but it is overall exothermic on the other three surfaces. The facets play an important role in the eliminating the ligand. We present DFT results on the activity of ceria-modified rutile TiO2 towards water dissociation and CO2 activation showing that this heterostructured catalyst can promote both reactions. This work will be important to reveal the mechanism and feasibility of atomic layer deposition of ceria on different TiO2 surface facets.

Influence of Selective Deposition of CeO2 and CuO on Surface MWCNTs Walls on the Activity, Selectivity and Stability in the PROX Reaction

Influence of Selective Deposition of CeO2 and CuO on Surface MWCNTs Walls on the Activity, Selectivity and Stability in the PROX Reaction

All-fabric flexible supercapacitor for energy storage

An all-fabric solid-state flexible supercapacitor has been fabricated using three types of commercial woven fabrics made of carbon fiber, activated carbon fiber, and polyester fiber, respectively. The activated carbon fiber fabric is viscose-based twill through carbonization and activation, followed by a deposition of CeO2 or ZnO nanoparticles through a hydrothermal process. The resultant fabric supercapacitor displays a high specific capacitance of 13.24 mF cm−2 at a scan rate of 0.2 mV s−1, an excellent capacitance retention of 87.6% at 5000 charge/discharge cycles, and a high energy density of 4.6 × 10−7 Wh cm−2 at a power density of 3.31 × 10−6 W cm−2. The supercapacitor is capable of bending in any angles without losing its performance, revealing an excellent flexibility. The facile, cost-effective fabrication process and excellent electrochemical performance allow this all-fabric solid-state flexible supercapacitor to be potentially used in new generation of wearable and self-powered electronic devices.

In vivo-induced size transformation of cerium oxide nanoparticles in both lung and liver does not affect long-term hepatic accumulation following pulmonary exposure.

Recent findings show that cerium oxide (CeO2) nanoparticles may undergo in vivo-induced size transformation with the formation of smaller particles that could result in a higher translocation following pulmonary exposure compared to virtually insoluble particles, like titanium dioxide (TiO2). Therefore, we compared liver deposition of CeO2 and TiO2 nanoparticles of similar primary sizes 1, 28 or 180 days after intratracheal instillation of 162 μg of NPs in female C57BL/6 mice. Mice exposed to 162 μg CeO2 or TiO2 nanoparticles by intravenous injection or oral gavage were included as reference groups to assess the amount of NPs that reach the liver bypassing the lungs and the translocation of NPs from the gastrointestinal tract to the liver, respectively. Pulmonary deposited CeO2 nanoparticles were detected in the liver 28 and 180 days post-exposure and TiO2 nanoparticles 180 days post-exposure as determined by darkfield imaging and by the quantification of Ce and Ti mass concentration by inductively coupled plasma-mass spectrometry (ICP-MS). Ce and Ti concentrations increased over time and 180 days post-exposure the translocation to the liver was 2.87 ± 3.37% and 1.24 ± 1.98% of the initial pulmonary dose, respectively. Single particle ICP-MS showed that the size of CeO2 nanoparticles in both lung and liver tissue decreased over time. No nanoparticles were detected in the liver following oral gavage. Our results suggest that pulmonary deposited CeO2 and TiO2 nanoparticles translocate to the liver with similar calculated translocation rates despite their different chemical composition and shape. The observed particle size distributions of CeO2 nanoparticles indicate in vivo processing over time both in lung and liver. The fact that no particles were detected in the liver following oral exposure showed that direct translocation of nanoparticles from lung to the systemic circulation was the most important route of translocation for pulmonary deposited particles.

Nanostructured TiO2 thin films sensitized by CeO2 as an inexpensive photoanode for enhanced photoactivity of water oxidation

Nanostructured CeO2/TiO2 bilayer thin films were fabricated by sequential deposition of CeO2 on TiO2 with varying the thickness of CeO2 using sol–gel spin-coating method. All samples were characterized by XRD, SEM, and UV–Visible absorption spectroscopy with an inspiration to use them as photoanode in photoelectrochemical splitting of water. The CeO2/TiO2 bilayer with the optimized thickness of CeO2 and TiO2 showed enhanced photoelectrochemical response of 2.1 mA cm-2 at 0.95 V/Ag/AgCl as compared to pristine CeO2 and TiO2. The improved photocurrent density of CeO2/TiO2 bilayer probably due to rapid transfer of charge carriers or electrical gradient at CeO2/TiO2 interface. This scalable and cost effective work with stable PEC performance of CeO2/TiO2 also shows the potential for realistic PEC applications.

Facile preparation of self-healing superhydrophobic CeO2 surface by electrochemical processes

Herein we report simple electrochemical processes to fabricate a self-healing superhydrophobic CeO2 coating on Type 304 stainless steel. The CeO2 surface anodically deposited on flat stainless steel surface is hydrophilic, although high temperature-sintered and sputter-deposited CeO2 surface was reported to be hydrophobic. The anodically deposited hydrophilic CeO2 surface is transformed to hydrophobic during air exposure. Specific accumulation of contaminant hydrocarbon on the CeO2 surface is responsible for the transformation to hydrophobic state. The deposition of CeO2 on hierarchically rough stainless steel surface produces superhydrophobic CeO2 surface, which also shows self-healing ability; the surface changes to superhydrophilic after oxygen plasma treatment but superhydrophobic state is recovered repeatedly by air exposure. This work provides a facile method for preparing a self-healing superhydrophobic surface using practical electrochemical processes.

Pt-CeO2/SiO2 catalyst for CO oxidation in humid air at ambient temperature

CO self-poisoning and slow surface kinetics pose major challenges to a CO oxidation catalyst that should work at ambient temperature. Furthermore, the presence of moisture would cause passivation of the catalyst. A highly active ceria promoted Pt catalyst (4%Pt-12%CeO2/SiO2; conversion ≥ 99% at low (< 500 ppm) and high (> 2500 ppm) CO concentrations was developed for CO oxidation at ambient temperature in humid air. Catalyst preparation variables such as Pt and CeO2 loading, ceria deposition method, drying and calcination conditions for the ceria and Pt precursors were optimized experimentally. The activity was correlated with surface properties using CO/H2 chemisorption, O2-H2 titration, X-ray diffraction and BET surface area analysis. The method of CeO2 deposition had a significant impact on the catalytic activity. CeO2 deposition by impregnation resulted in a catalyst that was three times more active than that prepared by deposition precipitation or CeO2 grafting. O2-H2 titration results revealed that the close association of ceria and Pt in the case of CeO2 deposition by impregnation resulted in higher activity. The catalyst support used was also crucial as a silica supported catalyst was five times more active than an alumina supported catalyst. The particle size and pore structure of the catalyst support were also crucial as the reaction was diffusion controlled. The drying and calcination conditions of the ceria and Pt precursors also played a crucial role in determining the catalytic activity. The Pt-CeO2/SiO2 catalysts with Pt > 2.5 wt% and CeO2 > 15 wt% were highly active (TOF > 0.02 s−1) and stable (conversion ≥ 99% after 15 h) at ambient conditions.

Synergistic effect of nitrate content and ethanol on photo-assisted anodic deposition of ceria thin films

Nanocrystalline ceria thin films have been prepared by photo-assisted anodic deposition in two kinds of solutions (water and 70% v/v ethanol-water) containing different sodium nitrate concentrations (0, 0.15, 0.20, 0.25 and 0.30moll−1) onto 316L surface. The synergistic effect of nitrate content and ethanol on the formation of ceria films was studied with scanning electron microscopy, ellipsometry, X-ray diffraction, and Raman, UV–visible, and X-ray photoelectron spectroscopy. Results show that the current density, film thickness, particle size and Ce(IV) content increase with increasing nitrate concentration in water solution whereas decrease in 70% v/v ethanol-water solution. When the nitrate concentration is higher than 0.25moll−1, the positive function of nitrate on the growth of ceria films is more prominent than ethanol. The action mechanism of nitrate on the photoelectrochemical deposition of CeO2 in two different solutions has been discussed in details.

CeO2-modified Au/TiO2 catalysts with outstanding stability under harsh CO oxidation conditions

The 1.5wt% Au/TiO2 World Gold Council catalyst (WGC) was modified by depositing on its surface a 5.4wt% CeO2 loading by incipient wetness impregnation. Calcination at 673K of the resulting, surface-modified, catalyst yielded a material in which the system of gold particles was not significantly modified with respect to that of the starting 1.5% Au/TiO2 WGC catalyst, neither in terms of its size distribution or metallic dispersion. The latter parameter remained, as in the catalyst prior to CeO2 deposition, in a value about 36%. Both catalysts, Au(1.5%)/TiO2 WGC and CeO2(5.4%)/Au(1.5%)/TiO2, were tested in consecutive CO oxidation reaction loops at increasing final temperatures. In these cycles, the ceria-modified catalyst showed not only a higher activity but, more importantly, a largely enhanced stability against deactivation. Scanning Transmission Electron Microscopy (STEM) studies clearly revealed the presence of nanometer-sized ceria rafts, less than 1nm thick, on the surface of the fresh CeO2(5.4%)/Au(1.5%)/TiO2 catalysts. After the CO oxidation test at the highest temperature, 1223K, the WGC catalyst suffered from a very severe Au nanoparticle sintering whereas Au nanoparticle growth was very much limited in the ceria-modified catalyst after the same aging test. STEM results reveal that a major fraction of the Au nanoparticles (75%), comprising all the smaller ones (<5nm), was contacting the ceria phase. This evidences an important stabilizing effect of the proposed surface modification. Moreover, these results open up possibilities for gold catalysts in applications where high temperatures are reached under working conditions.