Preparation of new solid superacid catalyst, zirconium sulfate supported on γ-alumina and activity for acid catalysis

Zirconium sulfate supported on γ-Al₂O₃ catalysts were prepared by impregnation of powdered γ-Al₂O₃ with zirconium sulfate aqueous solution followed by calcining in air at high temperature. For Zr(SO₄)₂/γ-Al₂O₃ samples, no diffraction line of zirconium sulfate was observed up to 50 wt.%, indicating good dispersion of Zr(SO₄)₂ on the surface of γ-Al₂O₃. The acidity of catalysts increased in proportion to the zirconium sulfate content up to 40 wt.% of Zr(SO₄)₂. 40-Zr(SO₄)₂/γ-Al₂O₃ calcined at 400 °C exhibited maximum catalytic activities for 2-propanol dehydration and cumene dealkylation. The catalytic activities for both reactions, 2-propanol dehydration and cumene dealkylation were correlated with the acidity of catalysts measured by ammonia chemisorption method.     

Opposite activation conditions of acid and metal functions of Pt/SO4-ZrO2 catalysts

The influence of the thermal treatments of Pt/SO₄²⁻-Zr(OH)₄ catalysts on the activity for the metal-catalyzed reaction of cyclohexane dehydrogenation and the acid-catalyzed reaction of n-butane isomerization, were studied in this work. A mutual antagonism between the conditions for optimal activity of the acid and metal functions was found and was seemingly related to the crystallization of the support. In order to be able to isomerize n-butane, SO₄²⁻-Zr(OH)₄ had first to be calcined in air at T^calc>400 °C. The onset of activity and strong acid properties coincided with the appearance of the tetragonal crystal phase. SO₄²⁻-Zr(OH)₄ supported Pt, prepared from chloroplatinic acid, was tried to be converted to the metal state (Pt⁰) in order to have full catalytic capacity. When Pt/SO₄²⁻-Zr(OH)₄ was first calcined in air at T^calc>400 °C, Pt remained in a seemingly oxidized state, with no de/hydrogenation properties even after reduction in H₂ at 300 °C. Under certain conditions, Pt metal properties were improved: (i) calcining Pt/SO₄²⁻-Zr(OH)₄ in air at T^calc<400 °C; (ii) calcining Zr(OH)₄ at T^calc>400 °C before sulfating the support; and (iii) calcining Pt/SO₄²⁻-Zr(OH)₄ in N₂ instead of air. In these cases, though Pt dehydrogenation activity increased, the activity of the acid function decreased (iii) or was practically null ((i) and (ii)). The support was amorphous in case (i) and mainly monoclinic in case (ii). Sulfate loss and conversion into the monoclinic phase occurred in case (iii). As compared to sulfate-free Pt/ZrO₂, sulfur poisoning always decreased the metal activity of sulfated catalysts but the decrease was higher for mainly tetragonal sulfate-doped catalysts. The final conclusion is that the optimum activation conditions for the metal and acid functions in Pt/SO₄²⁻-Zr(OH)₄ are mutually excluding. The deleterious effect of SO₄²⁻-ZrO₂ (SZ) on Pt metal activity is closely related to the growth and/or the presence of the tetragonal phase and cannot be prevented if a high activity of the acid function is demanded by the reacting system.     

Sulfuric acid formation over ammonium sulfate loaded V2O5–WO3/TiO2 catalysts by DeNOx reaction with NOx

Operating the SCR DeNO_x reactor at temperatures below 200 °C results in a considerable saving in operating costs. Plant experience shows that on the catalysts in these second generation DeNO_x plants, even for flue gases with SO₂ concentration below 10 mg/m³, over 1–2 years operating time sizeable quantities of ammonium sulfates accumulate. Ammonium sulfates deposited on V₂O₅–WO₃/TiO₂ catalysts react with NO_x to nitrogen and sulfuric acid. Second-order rate constants of this reaction for temperatures of 170 °C have been derived. It could be shown that the sulfuric acid formed on the catalyst is displaced by water vapour and desorbs resulting in gas phase concentrations of up to 6.5 mg acid/m³ flue gas. Plant equipment downstream of the ammonium sulfate containing low temperature DeNO_x catalysts has to be protected against the corrosive action of the sulfuric acid in the flue gases leaving the DeNO_x reactor.     

SO2 resistant antimony promoted V2O5/TiO2 catalyst for NH3-SCR of NOx at low temperatures

To get the low temperature sulfur resistant V₂O₅/TiO₂ catalysts quantum chemical calculation study was carried out. After selecting suitable promoters (Se, Sb, Cu, S, B, Bi, Pb and P), respective metal promoted V₂O₅/TiO₂ catalysts were prepared by impregnation method and characterized by X-ray diffraction (XRD) and Brunner Emmett Teller surface area (BET-SA). Se, Sb, Cu, S promoted V₂O₅/TiO₂ catalysts showed high catalytic activity for NH₃ selective catalytic reduction (NH₃-SCR) of NO_x carried at temperatures between 150 and 400 °C. The conversion efficiency followed in the order of Se > Sb > S > V₂O₅/TiO₂ > Cu but Se was excluded because of its high vapor pressure. An optimal 2 wt% ‘Sb’ loading was found over V₂O₅/TiO₂ for maximum NO_x conversion, which also showed high resistance to SO₂ in presence of water when compared to other metal promoters. In situ electrical conductivity measurement was carried out for Sb(2%)/V₂O₅/TiO₂ and compared with commercial W(10%)V₂O₅/TiO₂ catalyst. High electrical conductivity difference (ΔG) for Sb(2%)/V₂O₅/TiO₂ catalyst with temperature was observed. SO₂ deactivation experiments were carried out for Sb(2%)/V₂O₅/TiO₂ and W(10%)/V₂O₅/TiO₂ at a temperature of 230 °C for 90 h, resulted Sb(2%)/V₂O₅/TiO₂ was efficient catalyst. BET-SA, X-ray photoelectron spectroscopy (XPS) and carbon, hydrogen, nitrogen and sulfur (CHNS) elemental analysis of spent catalysts well proved the presence of high ammonium sulfate salts over W(10%)/V₂O₅/TiO₂ than Sb(2%)/V₂O₅/TiO₂ catalyst.     

Pt/TiO_2催化二甲醚部分氧化重整制氢

二甲醚是一种理想的氢载体,可用于解决氢的储存和运输。以Pt/TiO_2为部分氧化催化剂,结合Ni/Al_2O_3重整催化剂,考察钛前驱体和焙烧温度对二甲醚部分氧化重整制氢反应的影响。结果表明,以Ti(C4H9O)4为原料制备的TiO_2为金红石相,Ti(SO4)2或Ti O(OH)2为原料制备的TiO_2为锐钛矿相;以Ti(C4H9O)4为原料制备的Pt/TiO_2-E催化剂催化性能略好,转化率接近100%,H2收率约90%,表明金红石相TiO_2负载的Pt催化剂略佳;以Ti(SO4)2为原料制备的Pt/TiO_2-S催化剂500℃焙烧可获得金红石相TiO_2。与Pt/Al_2O_3催化剂相比,Pt/TiO_2催化剂具有更好的催化性能,H2收率超过90%,而Pt/Al_2O_3催化剂H2收率约80%。     

Decomposition of CCl2F2 over metal sulfate catalysts

Activity for hydrolysis of CCl₂F₂ (CFC12) on various metal sulfate was investigated. Zr(SO₄)₂ was found to be the most active while FeSO₄, Cr₂(SO₄)₃, Al₂(SO₄)₃, La₂(SO₄)₃ and Ce₂(SO₄)₃ had intermediate activity. MnSO₄, CoSO₄, and MgSO₄ showed low activity and SrSO₄, CaSO₄, and BaSO₄ had even less activity. The major carbon containing product was CO₂ and small amount of CClF₃ and CO were formed over several sulfates. The crystal structure of the sulfates was stable during decomposition of CCl₂F₂, and the conversion reached a steady state after initial decrease at 275 °C over Zr(SO₄)₂ catalyst. The concentration of surface hydroxyl was larger than that over AlPO₄-based catalysts and a reaction mechanism similar to that over AlPO₄-based catalysts was proposed.     

Catalytic decomposition of methylene chloride by sulfated oxide catalysts

Catalytic decomposition of methylene chloride in air with a concentration of 959 ppm and temperature ranges from 160 to 275°C were studied. Three different sulfated oxide catalysts, TiO₂(SO₄), ZrO₂(SO₄), CeO₂(SO₄) were prepared and their activities and selectivities were measured. The catalytic activity decreased in the order: TiO₂(SO₄) > ZrO₂(SO₄) > CeO₂(SO₄). Complete catalytic decomposition of methylene chloride was achieved at low temperature (275°C) over a sulfated titanium dioxide catalyst. The oxygen adsorption (pick-up) and the acidity values of three catalysts showed the same trend as their activities. The presence of water (2% in volume) in the feed stream reduced the activities remarkably and raised the activation energies for the decomposition reaction. The selectivities among all three catalysts were similar, with HCl, CO and CO₂ being the products. A bifunctional catalyst comprising sulfated titanium dioxide with copper oxide was developed to improve the selectivity of catalytic oxidation of methylene chloride towards carbon dioxide.     

EPR spectroscopic characterization of DeNOx and SO2 oxidation catalysts and model systems

The industrial SO₂ oxidation catalyst VK69 deactivates at around 440°C in a 10% SO₂, 11% O₂, 79% N₂ gas mixture. In situ EPR measurements show that the deactivation is caused by the precipitation of V(IV) compounds. DeNO_x catalysts based on V₂O₅/TiO₂, the TiO₂ support, analytical grade anatase and transition metal-exchanged Al-PILCs (pillared clay) have been characterized by EPR spectroscopy and the catalytic activity of the catalysts monitored up to 500°C. Depending on the exchanged metal ion, a relatively large temperature range for the catalytic activity towards the SCR reaction was observed.     

Effect of sulfate ions for sol–gel synthesis of titania photocatalyst

We have found that the use of sulfuric acid in the peptization process of sol–gel method produced SO₄²⁻-incorporated TiO₂ which is mechanically strong by firing at low temperature such as 200°C. The synthesized TiO₂ has larger specific surface area and retards the phase transition from anatase to rutile compared with that prepared from the peptization with nitric acid. The S-content of the TiO₂ fired at 200°C was 1.52 wt.%; the value has a maximum of 2.74 wt.% at 400°C. The XPS measurements indicate that S exists mainly as SO₄²⁻. The TiO₂ fired at 400°C showed the highest photocatalytic activity for ethylene degradation. Especially, we would like to emphasize the TiO₂ sintered at 200°C because they are extremely hard in spite of such a low sintering temperature. This photocatalyst may provide a great opportunity for extensive applications as self-supporting membranes.     

TiO2-SiO2 and V2O5/TiO2-SiO2 catalyst: Physico-chemical characteristics and catalytic behavior in selective catalytic reduction of NO by NH3

TiO₂-SiO₂ with various compositions prepared by the coprecipitation method and vanadia loaded on TiO₂-SiO₂ were investigated with respect to their physico-chemical characteristics and catalytic behavior in SCR of NO by NH₃ and in the undesired oxidation of SO₂ to SO₃, using BET, XRD, XPS, NH₃-TPD, acidity measurement by the titration method and activity test. TiO₂-SiO₂, compared with pure TiO₂, exhibits a remarkably stronger acidity, a higher BET surface area, a lower crystallinity of anatase titania and results in allowing a good thermal stability and a higher vanadia dispersion on the support up to high loadings of 15 wt% V₂O₅. The SCR activity and N₂ selectivity are found to be more excellent over vanadia loaded on TiO₂-SiO₂ with 10–20 mol% of SiO₂ than over that on pure TiO₂, and this is considered to be associated with highly dispersed vanadia on the supports and large amounts of NH₃ adsorbed on the catalysts. With increasing SiO₂ content, the remarkable activity decrease in the oxidation of SO₂ to SO₃, favorable for industrial SCR catalysts, was also observed, strongly depending on the existence of vanadium species of the oxidation state close to V⁴⁺ on TiO₂-SiO₂, while V⁵⁺ exists on TiO₂, according to XPS. It is concluded that vanadia loaded on Ti-rich TiO₂-SiO₂ with low SiO₂ content is suitable as SCR catalysts for sulfur-containing exhaust gases due to showing not only the excellent de-NO_x activity but also the low SO₂ oxidation performance.     

Preparation and characterization of sulfated TiO2 with rhodium modification used in esterification reaction and decomposition of methyl orange☆

A unique Rh/TiO_2 solid acid catalyst modified with H_2SO_4 was synthesized and evaluated in the esterification reaction of propylene glycol methyl ether and decomposition of methyl orange(MO) in aqueous phase under halogen lamp irradiation. For this purpose, rhodium(Rh) nanoparticles were loaded on SO_4~(2-)/TiO_2 via the photo-deposition method. It was found that SO_4~(2-)/Rh–TiO_2 exhibited stronger catalytic activity than SO_4~(2-)/TiO_2. The new catalysts were characterized by X-ray powder diffraction(XRD), Brunauer–Emmett–Teller(BET), Transmission electron microscopy(TEM) and high-resolution(HRTEM), X-ray photoelectron spectroscopy(XPS) and Fourier Transform infrared spectroscopy(FTIR). Results from XRD and BET show that SO_4~(2-)/Rh–TiO_2 has higher specific surface area and smaller pore size than SO42-/TiO_2. The distribution of loaded Rh was found to be uniform with a particle size of 2–4 nm. Data from XPS reveal that Rh primarily exists as Rh~0 and Rh~(3+)in Rh–TiO_2 and SO_4~(2)-/Rh–TiO_2. These valence forms of Rh likely contribute to the enhanced catalytic activity. Furthermore, FT-IR spectra of the catalysts show an abundance of surface hydroxyl groups, which help the formation of hydroxyl radicals and the enhancement of surface acid density. The results show that more acid sites are formed on the sulfated Rh–TiO_2, and these acidic sites are largely responsible for improving the catalytic performance. This superior SO_4~(2-)/Rh–TiO_2 catalyst has potential applications in reactions requiring efficient acid catalysts, including esterification reactions and waste water treatment.     

Molecular structure–reactivity relationships for the oxidation of sulfur dioxide over supported metal oxide catalysts

The catalytic oxidation of sulfur dioxide to sulfur trioxide over several binary (M_xO_y/TiO₂) and ternary (V₂O₅/M_XO_Y/TiO₂) supported metal oxide catalysts was systematically investigated. The supported metal oxide components were essentially 100% dispersed as surface metal oxide species, as confirmed by Raman spectroscopy characterization. The sulfur dioxide oxidation turnover frequencies of the binary catalysts were all within an order of magnitude (V₂O₅/TiO₂>Fe₂O₃/TiO₂>Re₂O₇/TiO₂  CrO₃/TiO₂  Nb₂O₅/TiO₂>MoO₃/TiO₂  WO₃/TiO₂). An exception was the K₂O/TiO₂ catalysts, which is essentially inactive for sulfur dioxide oxidation. With the exception of K₂O, all of the surface metal oxide species present in the ternary catalysts (i.e., oxides of V, Fe, Re, Cr, Nb, Mo and W) can undergo redox cycles and oxidize SO₂ to SO₃. The turnover frequency for sulfur dioxide oxidation over all of these catalysts is approximately the same at both low and high surface coverages. This indicates that the mechanism of sulfur dioxide oxidation is not sensitive to the coordination of the surface metal oxide species. A comparison of the activities of the ternary catalysts with the corresponding binary catalysts suggests that the surface vanadium oxide and the additive surface metal oxide redox sites act independently without synergistic interactions. The V₂O₅/K₂O/TiO₂ catalyst showed a dramatic reduction in the catalytic activity in comparison to the unpromoted V₂O₅/TiO₂ catalyst. The ability of K₂O to significantly retard the redox potential of the surface vanadia species is primarily responsible for the lower catalytic activity of the ternary catalytic system. The fundamental insights generated from this research can potentially assist in the molecular design of the air pollution control catalysts: (1) the development of catalysts for low temperature oxidation of SO₂ to SO₃ during sulfuric acid manufacture (2) the design of efficient SCR DeNO_x catalysts with minimal SO₂ oxidation activity and (3) improvements in additives for the simultaneous oxidation/sorption of sulfur oxides in petroleum refinery operations.     

低温选择性催化还原催化剂二氧化硫中毒及再生特性

采用液相共沉淀法制备Mn-Ce/TiO₂低温选择性催化还原催化剂,催化剂在120 ℃无二氧化硫条件下低温SCR活性高,NO转化率为92%。利用BET、SEM、TEM、XRD和XPS等技术对催化剂的二氧化硫中毒特性进行分析,结果表明,催化剂中毒是由于(NH₄)₂SO₃和(NH₄)₂SO₄在催化剂表面发生沉积,采用水洗、加热和还原气体保护加热等方式对催化剂进行再生实验,发现水洗对催化剂活性再生非常有效,特别是在水洗浸泡过程中采用超声波震荡。用离子色谱技术对水洗副产物进行分析,发现水洗液中主要离子为NO₃^-、SO₄^2--和NH₄^+。     

超声浸渍无机盐改性Hβ分子筛催化合成乙基蒽醌

采用超声浸渍法将无机盐Al₂(SO₄)₃、(NH₄)₂SO₄、Ce(NH₄)₂(NO₃)₆和Fe(NO₃)₃负载于Hβ分子筛上,通过NH₃-TPD、XRD和吡啶-IR对分子筛进行表征,考察改性前后分子筛酸性能和晶相的变化。将改性的Hβ分子筛用于催化乙苯和苯酐合成乙基蒽醌。结果表明,不同无机盐超声浸渍改性分子筛的催化效果差别较大,其中,每克分子筛负载0.2 g的Al₂(SO₄)₃的Alβ分子筛催化效果最好,苯酐转化率为45.67%,乙基蒽醌选择性为50.12%。分子筛的酸性能（包括酸量、酸种类和酸强度）对催化性能影响较大。     

Role of lanthanide elements on the catalytic behavior of supported Pd catalysts in the reduction of NO with methane

In this study, the role of lanthanide elements (Ce, Gd, La, and Yb) on Pd/TiO₂ catalysts in the catalytic reduction of NO with methane was investigated. Steady-state reaction experiments in the presence of oxygen showed that the addition of lanthanide elements increases the oxygen resistance of the catalyst. The post-reaction XPS characterization results revealed that majority of the Pd sites remained in the zero oxidation state in the presence of Ce or Gd. The effect of SO₂ (145 ppm) and H₂O (0–6.6%) in NO–CH₄–O₂ reaction over supported Pd and Gd–Pd catalysts was also investigated. Over the Gd–Pd catalyst with the presence of SO₂, more than 70% NO conversion was obtained for over 6 h while the Pd only catalyst showed a sharper drop in NO conversion. Over the Gd–Pd catalyst, the presence of H₂O showed no effect on NO conversion activity (>99% conversion) during the 18 h the catalyst was kept on stream. Among the lanthanide elements tested, Gd is the most effective, allowing the use of above stoichiometric oxygen concentration.     

A comparative study of TiO2 supported noble metal catalysts for the oxidation of formaldehyde at room temperature

The TiO₂ supported noble metal (Au, Rh, Pd and Pt) catalysts were prepared by impregnation method and characterized by means of X-ray diffraction (XRD) and BET. These catalysts were tested for the catalytic oxidation of formaldehyde (HCHO). It was found that the order of activity was Pt/TiO₂  Rh/TiO₂ > Pd/TiO₂ > Au/TiO₂  TiO₂. HCHO could be completely oxidized into CO₂ and H₂O over Pt/TiO₂ in a gas hourly space velocity (GHSV) of 50,000 h⁻¹ even at room temperature. In contrast, the other catalysts were much less effective for HCHO oxidation at the same reaction conditions. HCHO conversion to CO₂ was only 20% over the Rh/TiO₂ at 20 °C. The Pd/TiO₂ and Au/TiO₂ showed no activities for HCHO oxidation at 20 °C. The different activities of the noble metals for HCHO oxidation were studied with respect to the behavior of adsorbed species on the catalysts surface at room temperature using in situ DRIFTS. The results show that the activities of the TiO₂ supported Pt, Rh, Pd and Au catalysts for HCHO oxidation are closely related to their capacities for the formation of formate species and the formate decomposition into CO species. Based on in situ DRIFTS studies, a simplified reaction scheme of HCHO oxidation was also proposed.     

Interpretation of the chain structures of PMMAs, PANs and PAAms obtained by using Ce(IV) and KMnO4 in combination with NTA and DTPA as initiator systems by FTIR spectroscopic analysis

Polyacrylamides (PAAms), polyacrylonitriles (PANs) and poly(methyl methacrylate)s (PMMAs) were synthesized by using Ce(NH₄)₂(NO₃)₆, Ce(SO₄)₂·4H₂O and KMnO₄ in combination with nitrilotriacetic acid (NTA) and diethylenetriamine pentaacetic acid (DTPA), which have strong chelating properties, as redox initiators. Polymerizations were carried out in the aqueous acidic solutions at 25°C and 55°C in the presence of air. The chain structures of the resulting products were studied by Fourier-transform infrared (FTIR) spectroscopic measurements. From the comparison of the spectroscopic results with gravimetric and viscometric data it was concluded that both the differences between the solubility behaviour in aqueous solutions of MMA, AN, AAm and their polymers, and catalyst–activator–monomer combinations were important parameters effecting the polymerization mechanisms, conversions and the structures of the polymers. The FTIR and viscosity results indicated that PAAms obtained in our experimental conditions formed crosslinked structures with sulphated complexes of Ce(III) and MnSO₄ produced by the redox reactions between catalysts (MnO₄⁻ and Ce(IV)), NTA and AAm. Further, it was observed that PAN chains were terminated by hydrated and sulphated complexes of Ce(III) while the termination of PMMA radicals took place by primary radicals because PMMAs were formed by emulsion polymerization kinetics.     

Tailoring of alumina surfaces as supports for NiMo sulfide catalysts in the ultra deep hydrodesulfurization of gas oil: case study of TiO2-coated alumina prepared by chemical vapor deposition technique

The present paper gives a detailed review of the different studies under investigation in our laboratory concerning the use of TiO₂ and TiO₂–Al₂O₃ composites prepared by chemical vapor deposition (CVD) as support for sulfide catalysts in the HDS of dibenzothiophene (DBT) derivatives. The supports investigated here are: TiO₂ (from Degussa, 50 m²/g), Al₂O₃ (Nikki, 186 m²/g) and TiO₂–Al₂O₃ supports prepared by CVD of TiCl₄ on alumina. Using several characterization techniques, we have demonstrated that the support composite presents a high dispersion of TiO₂ over γ-Al₂O₃ without forming precipitates up to ca. 11 wt.% loading. Moreover, the textural properties of the support composite are comparable to those of alumina. XPS investigations of Mo and NiMo catalysts supported on the different carriers show that Mo-oxide species exhibit a higher degree of sulfidation on the surface of TiO₂ and TiO₂–Al₂O₃ than on alumina. The HDS tests of 4,6-DMDBT under mild operating conditions (573 K, 3 MPa) show that sulfide catalysts supported on the composite support (ca. 11 wt.%) are more active than those supported on to TiO₂ or Al₂O₃. This higher HDS catalytic activity is attributed to the promotion of the hydrodesulfurization pathway, whereby the pre-hydrogenation of one of the aromatic rings adjacent to the thiophenic one may reduce the steric hindrance caused by the two methyl groups adjacent to the sulfur atom during the C–S bond cleavage.     

A regenerable Fe/AC desulfurizer for SO2 adsorption at low temperatures

A novel regenerable Fe/activated coke (AC) desulfurizer prepared by impregnation of Fe(NO₃)₃ on an activated coke was investigated. Experiment results showed that at 200 °C the SO₂ adsorption capacity of the Fe/AC was higher than that of AC or Fe₂O₃. Temperature-programmed desorption (TPD) revealed that H₂SO₄ and Fe₂(SO₄)₃ were generated on the desulfurizer upon adsorption of SO₂. Effect of desulfurization temperature was also investigated which revealed that with increasing temperature from 150 to 250 °C, the SO₂ removal ability gradually increases. The used Fe/AC can be regenerated by NH₃ at 350 °C to directly form solid ammonium-sulfate salts.     

Gold nanoparticles supported on ceria-modified mesoporous titania as highly active catalysts for low-temperature water-gas shift reaction

New gold catalytic system prepared on ceria-modified mesoporous titania (CeMTi) used as water-gas shift (WGS) reaction catalyst is reported. Mesoporous titania (MTi) was synthesized using surfactant templating method through a neutral [C₁₃(EO)₆–Ti(OC₃H₇)₄] assembly pathway. Ceria modifying additive was deposited on MTi by deposition precipitation (DP) method. Gold-based catalysts with different gold content (1–5 wt.%) were synthesized by DP of gold hydroxide on mixed metal oxide support. The supports and the catalysts were characterized by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), N₂ adsorption analysis and temperature-programmed reduction (TPR). The catalytic behavior of the gold-based catalysts was evaluated in WGS reaction in a wide temperature range (140–300 °C) and at different space velocities and H₂O/CO ratios. The influence of gold content and particle size on the catalytic performance was investigated. The WGS activity of the new gold/ceria-modified mesoporous titania catalysts was compared with that of gold catalysts supported on simple oxides CeO₂ and mesoporous TiO₂, as well as gold/ceria-modified titania and reference catalyst Au/TiO₂ type A (World Gold Council). A high degree of synergistic interaction between ceria and mesoporous titania and a positive modification of structural and catalytic properties by ceria has been achieved. It is clearly revealed that the ceria-modified mesoporous titania is of much interest as potential support for gold-based catalyst. The Au/ceria-modified mesoporous titania catalytic system is found to be efficient catalyst for WGSR.