Preparation and characterization of LaFe1−xMgxO3/Al2O3/FeCrAl: Catalytic properties in methane combustion

MnO_x–CeO₂ mixed oxides prepared by sol–gel method, coprecipitation method and modified coprecipitation method were investigated for the complete oxidation of formaldehyde. Structure analysis by H₂-TPR and XPS revealed that there were more Mn⁴⁺ species and richer lattice oxygen on the surface of the catalyst prepared by the modified coprecipitation method than those of the catalysts prepared by sol–gel and coprecipitation methods, resulting in much higher catalytic activity toward complete oxidation of formaldehyde. The effect of calcination temperature on the structural features and catalytic behavior of the MnO_x–CeO₂ mixed oxides prepared by the modified coprecipitation was further examined, and the catalyst calcined at 773 K showed 100% formaldehyde conversion at a temperature as low as 373 K. For the samples calcined below 773 K, no any diffraction peak corresponding to manganese oxides could be detected by XRD measurement due to the formation of MnO_x–CeO₂ solid solution. While the diffraction peaks corresponding to MnO₂ phase in the samples calcined above 773 K were clearly observed, indicating the occurrence of phase segregation between MnO₂ and CeO₂. Accordingly, it was supposed that the strong interaction between MnO_x and CeO₂, which depends on the preparation route and the calcination temperature, played a crucial role in determining the catalytic activity toward the complete oxidation of formaldehyde.     

Catalytic combustion of hydrocarbons with Mn and Cu-doped ceria–zirconia solid solutions

The catalytic activity of a series of CeO₂–ZrO₂ mixed oxides in the total oxidation of methane and light hydrocarbons has been investigated. The influence of dopants like Mn and Cu has also been studied. It is shown that both MnO_x and CuO at low loading dissolve within the ceria–zirconia lattice. This strongly influences the redox behaviour of the catalysts by promoting low-temperature reduction of Ce⁴⁺. In addition, the ternary oxides show better stability to repeated redox cycles, which is attributed to the presence of ZrO₂. The catalytic activity of pure CeO₂ is also enhanced in the presence of ZrO₂, reaching a maximum with Ce_0.92Zr_0.08O₂; a further promotion of activity is observed with the introduction of MnO_x and CuO dissolved into CeO₂–ZrO₂ lattice.     

Direct decomposition of nitric oxide over Ba catalysts supported on CeO2-based mixed oxides

The direct decomposition of nitric oxide (NO) over barium catalysts supported on various metal oxides was examined in the absence and presence of O₂. Among the Ba catalysts supported on single-component metal oxides, Ba/Co₃O₄ and Ba/CeO₂ showed high NO decomposition activities, while Ba/Al₂O₃, Ba/SiO₂, and Ba/TiO₂ exhibited quite low activities. The effect of an addition of second components to Co and Ce oxides was further examined, and it was found that the activities were significantly enhanced using Ce–Mn mixed oxides as support materials. XRD results indicated the formation of CeO₂–MnO_x solid solutions with the cubic fluorite structure. O₂-TPD of the CeO₂–MnO_x solid solutions showed a large desorption peak in a range of relatively low temperature. The BET surface areas of the CeO₂–MnO_x solid solutions were larger than those of pure CeO₂ and Mn₂O₃. These effects caused by the addition of Mn are responsible for the enhanced activities of the Ba catalysts supported on Ce–Mn mixed oxides.     

Selective reduction of NO by NH3 over manganese–cerium mixed oxides: Relation between adsorption, redox and catalytic behavior

Manganese–cerium mixed oxide catalysts with different molar ratio Mn/(Mn + Ce) (0, 0.25, 0.50, 0.75, 1) were prepared by citric acid method and investigated concerning their adsorption behavior, redox properties and behavior in the selective catalytic reduction of NO_x by NH₃. The studies based on pulse thermal analysis combined with mass spectroscopy and FT-IR spectroscopy uncovered a clear correlation between the dependence of these properties and the mixed oxide composition. Highest activity to nitrogen formation was found for catalysts with a molar ratio Mn/(Mn + Ce) of 0.25, whereas the activity was much lower for the pure constituent oxides. Measurements of adsorption uptake of reactants, NO_x (NO, NO₂) and NH₃, and reducibility showed similar dependence on the mixed oxide composition indicating a clear correlation of these properties with catalytic activity. The adsorption studies indicated that NO_x and NH₃ are adsorbed on separate sites. Consecutive adsorption measurements of the reactants showed similar uptakes as separate measurements indicating that there was no interference between adsorbed reactants. Mechanistic investigations by changing the sequence of admittance of reactants (NO_x, NH₃) indicated that at 100–150 °C nitrogen formation follows an Eley–Rideal type mechanism, where adsorbed ammonia reacts with NO_x in the gas phase, whereas adsorbed NO_x showed no significant reactivity under conditions used.     

NOx storage and reduction characteristics of Pd/MnOx–CeO2 at low temperature

The reaction between hydrogen and NO was studied over 1 wt.% Pd supported on NO_x-sorbing material, MnO_x–CeO₂, at low temperatures. The result of pulse mode reactions suggest that NO_x adsorbed as nitrate and/or nitrite on MnO_x–CeO₂ was reduced by hydrogen, which was spilt-over from Pd catalyst. The NO_x storage and reduction (NSR) cycles were carried out over Pd/MnO_x–CeO₂ in a conventional flow reactor at 150 °C. In a storage step, NO was removed by the oxidative adsorption from a stream of 0.04–0.08% NO, 5–10% O₂, and He balance. This was followed by a reducing step, where a stream of 1% H₂/He was supplied to ensure the conversion of nitrate/nitrite to N₂ and thus restore the adsorbability. It was revealed that the NSR cycle is much more suitable for the H₂–deNO_x process in excess O₂, compared to a conventional steady state reaction mode.     

Catalytic combustion of methane over microemulsion-derived MnOx–Cs2O–Al2O3 nanocomposites

Mesostructured MnO_x–Cs₂O–Al₂O₃ nanocomposites have been synthesized by reverse microemulsion method combined with hydrothermal treatment and then applied to the catalytic combustion of methane. Compared to impregnation-derived conventional MnO_x/Cs₂O/Com-Al₂O₃ catalyst, the microemulsion-derived catalyst showed higher activity and stability for methane combustion. The T_10% of the fresh and of the 72 h aged Mn_xO–Cs₂O–Al₂O₃ were 475 and 490 °C, respectively, recommending it as a potential candidate catalyst for application in hybrid gas turbines. The homogeneous composition of the microemulsion-derived nanocomposite catalyst can hinder the loss of Cs⁺ and accelerate the formation of Cs–β-alumina phase, ensuring thus higher activity and stability for methane combustion.     

Total oxidation catalysts based on manganese or copper oxides and platinum or palladium I: Characterisation

Temperature-programmed reduction (TPR), oxidation (TPO), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to characterise catalysts based on manganese oxides, copper oxides or one of them mixed with platinum or palladium-supported on γ-alumina. The catalysts were characterised before and after they had been exposed either to high temperature in the presence of steam or to sulphur dioxide. Raman spectroscopy, XRD, XPS and TPR performed on the fresh samples of MnO_x, mixed MnO_x–Pt and MnO_x–Pd revealed the presence of a mixture of manganese oxides, particularly Mn₂O₃. In the fresh mixed MnO_x–Pd and CuO_x–Pd samples, Pd catalysed the reduction of both MnO_x and CuO_x, whereas Pt only catalysed the reduction of MnO_x. After hydrothermal treatment at 900°C of the MnO_x, mixed MnO_x–Pt and MnO_x–Pd samples, there was a formation of new manganese oxide phase, Mn₃O₄ detected by Raman spectroscopy. TPR revealed increasing interaction between the metal oxides and the noble metals in the hydrothermally treated mixed MnO_x–Pd and CuO_x–Pd samples, and also the appearance of interaction in the treated mixed CuO_x–Pt sample. The sulphur adsorbed in all the MnO_x samples formed sulphate, which was more difficult to reduce than the oxides. Also, the reduction temperature of sulphates was lowered when noble metals are present.     

Total oxidation catalysts based on manganese or copper oxides and platinum or palladium II: Activity, hydrothermal stability and sulphur resistance

Deactivation of catalysts based on either manganese oxides, copper oxides, platinum, palladium or combinations of these metal oxides and noble metals supported on γ-alumina was studied. The activity of the catalysts for the oxidation of carbon monoxide, naphthalene and methane, in a mixture resembling the flue gases from wood combustion, was measured before and after exposure of the catalysts either to a temperature of 900°C in the presence of steam or to sulphur dioxide. Most of the mixed catalysts were more resistant to hydrothermal and sulphur treatments than the catalysts with a single active component. After the hydrothermal treatment the activity of the MnO_x catalyst was enhanced. When Pt is combined with MnO_x or CuO_x, the loss of activity of Pt was decreased during the hydrothermal treatment. Also, the hydrotreated mixed MnO_x–Pd and CuO_x–Pd catalysts were more active than the treated Pd catalyst for the oxidation of methane. After sulphur treatment, the activities of the mixed MnO_x–Pt (Pt: 0.05 mol%), MnO_x–Pd and CuO_x–Pd catalysts were improved for the oxidation of carbon monoxide and naphthalene. Among the catalysts studied, the MnO_x–Pt, CuO_x–Pt and CuO_x–Pd catalysts, with a metal oxide and a noble metal loading of 10 and 0.1 mol%/γ-alumina, respectively, had the best combination of activity, thermal stability and resistance to sulphur treatment.     

The SMSI between supported platinum and CeO2–ZrO2–La2O3 mixed oxides in oxidative atmosphere

CeO₂–ZrO₂–La₂O₃ (CZL) mixed oxides were prepared by citric acid sol–gel method. The as-received gel was calcined at 500, 700, 900 and 1050 °C to obtain the so-called C5, C7, C9 and CK, respectively. The C5, C7 and C9 powders were impregnated with H₂PtCl₆ and then calcined at 500 °C to prepare P5C5, P5C7 and P5C9, respectively. The impregnated CK powders were calcined at 500, 700 and 900 °C to prepare P5CK, P7CK and P9CK, respectively. The XRD and XPS analyses show that the surface distribution of Pt is evidently influenced by the structural and textural properties of the support. The CO adsorption followed by FTIR reveals that the dispersion and the chemisorption sites of Pt are reduced as the calcination temperature of CZL support increases. The chemisorption ability of the CK samples is even completely deactivated. The encapsulation mechanism, which has been applied to explain the so-called strong metal–support interaction (SMSI) after reductive treatment, is introduced here to demonstrate the abnormal observations though the samples were prepared in oxidative atmosphere. The HRTEM results also confirm this explanation. The effects of oxygen vacancies, the chemisorption sites on the Pt surface and Pt/Ce interfacial sites on the three-way catalytic activities are discussed.     

Structure evolution of nanocrystalline CeO2 and CeLnOx mixed oxides (Ln = Pr, Tb, Lu) in O2 and H2 atmosphere and their catalytic activity in soot combustion

This paper reports results of studies on structure and activity in soot combustion of nanocrystalline CeO₂ and CeLnOx mixed oxides (Ln = Pr, Tb, Lu, Ce/Ln atomic ratios 5/1). Nano-sized (4–5 nm) oxides with narrow size distribution were prepared by a microemulsion method W/O. Microstructure, morphology and reductivity of the oxides annealed up to 950 °C in O₂ and H₂ were analyzed by HRTEM, XRD, FT-IR, Raman spectroscopy and H₂-TPR. Obtained mixed oxides had fluorite structure of CeO₂ and all exhibited improved resistance against crystal growth in O₂, but only CeLuOx behaved better than CeO₂ in hydrogen.

The catalytic activity of CeO₂, CeLnOx and physical mixtures of CeO₂ + Ln₂O₃ in a model soot oxidation by air was studied in “tight contact” mode by using thermogravimetry. Half oxidation temperature T_1/2 for soot oxidation catalysed by nano-sized CeO₂ and CeLnOx was similar and ca. 100 °C lower than non-catalysed oxidation. However, the mixed oxides were much more active during successive catalytic cycles, due to better resistance to sintering. Physical mixtures of nanooxides (CeO₂ + Ln₂O₃) showed exceptionally high initial activity in soot oxidation (decrease in T_1/2 by ca. 200 °C) but degraded strongly in successive oxidation cycles. The high initial activity was due to the synergetic effect of nitrate groups present in highly disordered surface of nanocrystalline Ln₂O₃ and enhanced reductivity of nanocrystalline CeO₂.     

Development of new catalysts for N2O-decomposition from adipic acid plant

Direct decomposition of N₂O was investigated using simulated and real industrial gas stream coming from an adipic acid plant. Two different kinds of catalysts were studied: (i) LaB_1−xB′_xO₃ and CaB_1−xCu_xO₃ (B = Mn, Fe and B′ = Cu, Ni) perovskites (PVKs) and (ii) supported PVKs (10 or 20 wt.%) on γ-Al₂O₃ and CeO₂–ZrO₂. The structural modifications induced by the composition of PVK samples affect the catalytic performances: mixed oxide formation in CaMn_0.7Cu_0.3O₃ samples allows to reach the highest values of N₂O conversion while the effect of PVK phases is more controversial. The importance of copper on catalytic activities is confirmed by the investigation on CaMn_1−xCu_xO₃ samples. The best results were obtained with a CaMn_0.6Cu_0.4O₃ catalyst calcined at 700 °C for 5 h, in which the presence of copper maximises the Ca₃CuMnO₆ phase formation. The increase in Cu-content produces a large segregation of CuO despite PVK formation. The best catalyst was tested using industrial gas stream, showing good stability also in the presence of H₂O and O₂ (8% v/v ) after 1400 h on-stream. To increase surface area, Cu-containing PVKs were deposed on γ-Al₂O₃ and CeO₂–ZrO₂, and this latter has been recognised as the best support. Indeed, the activity of the PVKs supported on ceria–zirconia is comparable to and even better than that of the bulk catalysts. A possible explanation regards the support contribution in terms of activity and/or promotion of O₂ mobility which enhances the overall activity of the catalyst.     

Role of CeO2 in Ni/CeO2–Al2O3 catalysts for carbon dioxide reforming of methane

Ni catalysts supported on γ-Al₂O₃, CeO₂ and CeO₂–Al₂O₃ systems were tested for catalytic CO₂ reforming of methane into synthesis gas. Ni/CeO₂–Al₂O₃ catalysts showed much better catalytic performance than either CeO₂- or γ-Al₂O₃-supported Ni catalysts. CeO₂ as a support for Ni catalysts produced a strong metal–support interaction (SMSI), which reduced the catalytic activity and carbon deposition. However, CeO₂ had positive effect on catalytic activity, stability, and carbon suppression when used as a promoter in Ni/γ-Al₂O₃ catalysts for this reaction. A weight loading of 1–5 wt% CeO₂ was found to be the optimum. Ni catalysts with CeO₂ promoters reduced the chemical interaction between nickel and support, resulting in an increase in reducibility and stronger dispersion of nickel. The stability and less coking on CeO₂-promoted catalysts are attributed to the oxidative properties of CeO₂.     

Promotion effect of residual K on the decomposition of N2O over cobalt–cerium mixed oxide catalyst

A series of cobalt–cerium mixed oxide catalysts (Co₃O₄–CeO₂) with a Ce/Co molar ratio of 0.05 were prepared by co-precipitation (with K₂CO₃ and KOH as the respective precipitant), impregnation, citrate, and direct evaporation methods and then tested for the catalytic decomposition of N₂O. XRD, BET, XPS, O₂-TPD and H₂-TPR methods were used to characterize the catalysts. Catalysts with a trace amount of residual K exhibited higher catalytic activities than those without. The presence of appropriate amount of K in Co₃O₄–CeO₂ may improve the redox property of Co₃O₄, which is important for the decomposition of N₂O. When the amount of K was constant, the surface area became the most important factor for the reaction. The co-precipitation-prepared catalyst with K₂CO₃ as precipitant exhibited the best catalytic performance because of the presence of ca. 2 mol% residual K and the high surface area. We also discussed the rate-determining step of the N₂O decomposition reaction over these Co₃O₄–CeO₂ catalysts.     

Design of advanced automotive exhaust catalysts

Rhodium (Rh) is a critical component of current automotive three-way catalysts (TWCs), particularly with regard to NO_x and CO conversion at rich and stoichiometric air–fuel ratios (A/F). Rh supported on CeO₂ was active for NO_x and CO conversions but could be deactivated easily by high temperature aging. The cause of the deactivation is ascribed to the sintering of CeO₂. ZrO₂ incorporation into CeO₂ is reported to have high thermal durability in terms of oxygen storage capacity (OSC). There has been no report showing direct experimental evidence that Rh-loaded on CeO₂–ZrO₂ mixed oxides induced effects on TWC performance improvement in the actual automotive exhaust. In the present paper, the Rh-CeO₂ interaction contributing to NO_x reduction and the catalytic behavior of Rh-loaded CeO₂–ZrO₂ mixed oxide is addressed. Incorporating CeO₂–ZrO₂ into a catalyst offered significant improvement in light-off and warmed-up performances in model gas test. Newly designed TWC including the Rh/CeO₂–ZrO₂ component were aged and evaluated on an engine dynamometer. Result of engine dynamometer evaluation also revealed that significant improvement in the thermal durability can be achieved by the utilization of the optimized Rh-loaded CeO₂–ZrO₂ mixed oxide.     

Effect of ceria–zirconia ratio on the interaction of CO with PdO/Al2O3–(Cex–Zr1−x)O2 catalysts prepared by sol–gel method

The current work is devoted to study of CO interaction with PdO/Al₂O₃–(Ce_x–Zr_1−x)O₂ catalysts. Ceria–zirconia–alumina supports with different Ce/Zr ratio were prepared by sol–gel technique. The FT-IR characterization of CO adsorbed at −120 and 25 °C on oxidized and reduced samples revealed that Ce/Zr ratio modifies the surface properties of support and oxidation state of palladium. The catalyst with Ce/Zr molar ratio 0.5/0.5 was characterized with the highest ability to stabilize palladium in oxide state and the highest activity to oxidize CO. Redox treatment of catalysts improves their catalytic activity.     

Thermal ageing of Pt on low-surface-area CeO2–ZrO2–La2O3 mixed oxides: Effect on the OSC performance

This work aims at exploring the thermal ageing mechanism of Pt on ceria-based mixed oxides and the corresponding effect on the oxygen storage capacity (OSC) performance of the support material. Pt was supported on low-surface-area CeO₂–ZrO₂–La₂O₃ mixed oxides (CK) by impregnation method and subsequently calcined in static air at 500, 700 and 900 °C, respectively. The evolutions of textural, microstructural and redox properties of catalysts after the thermal treatments were identified by means of X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (TPR) and high-resolution transmission electron microscope (HRTEM). The results reveal that, besides the sintering of Pt, encapsulation of metal by the mixed oxides occurs at the calcination temperature of 700 °C and above. The burial of Pt crystallites by support particles is proposed as a potential mechanism for the encapsulation. Further, the HRTEM images show that the distortion of the mixed oxides lattice and other crystal defects are distributed at the metal/oxides interface, probably indicating the interdiffusion/interaction between the metal and mixed oxide. In this way, encapsulation of Pt is capable to promote the formation of Ce³⁺ or oxygen vacancy on the surface and in the bulk of support. The OSC results show that the reducibility and oxygen release behavior of catalysts are related to both the metal dispersion and metal/oxides interface, and the latter seems to be more crucial for those supported on low-surface-area mixed oxides. Judging by the dynamic oxygen storage capacity (DOSC), oxygen storage capacity complete (OSCC) and oxygen releasing rate, the catalyst calcined at 700 °C shows the best OSC performance. This evident promotion of OSC performance is believed to benefit from the partial encapsulation of Pt species, which leads to the increment of Ce³⁺ or oxygen vacancies both on the surface and in the bulk of oxides despite a loss of chemisorption sites on the surface of metal particles.     

Oxidative degradation properties of Co-based catalysts in the presence of ozone

Four series of cobalt-based catalysts, such as bare Co₃O₄ and CoO, CoO_x–CeO₂ mixed oxides, CoO_x supported over alumina and alumina–baria and CoMgAl and CoNiAl hydrotalcites have been synthesized and investigated for the oxidative degradation of phenol in the presence of ozone. Characterizations were obtained by several techniques in order to investigate the nature of cobalt species and their morphological properties, depending on the system. Analyses by XRD, BET, TPR, UV–visible diffuse reflectance spectroscopy and TG/DT were performed.

The CoNiAl hydrotalcite exhibits, after 4 h of reaction, the highest phenol ozonation activity followed by Co(3 wt%)/Al₂O₃–BaO and CoMgAl. The samples Co(1 wt%)/Al₂O₃–BaO and Co(1 and 3 wt%)/Al₂O₃ show a comparable medium activity, while the oxidation properties of bare oxides Co₃O₄, CoO and CoO_x–CeO₂ are really low. Leaching of cobalt ions in the water solution was detected during the reaction, the amount varied depending on the nature of catalysts. A massive release was observed for the CoMgAl and CoNiAl hydrotalcites, while cobalt catalysts over alumina and alumina–baria look much more stable. The recycle of CoO_x/Al₂O₃ and CoO_x/Al₂O₃–BaO was studied by performing three consecutive cycles in the phenol oxidation. Because of the potential interest of the cobalt-supported catalysts in the ozonation process, the oxidative degradation of naphtol blue black was also investigated.

On the basis of TPR and UV–visible results it appears that highly dispersed Co²⁺ ions especially present over Co(3 wt%)/Al₂O₃–BaO are the main active sites for phenol and naphtol blue black oxidative degradation by ozone.     

MnOx/Pt/Al2O3 catalysts for CO oxidation in H2-rich streams

The catalytic activity of Pt on alumina catalysts, with and without MnO_x incorporated to the catalyst formulation, for CO oxidation in H₂-free as well as in H₂-rich stream (PROX) has been studied in the temperature range of 25–250 °C. The effect of catalyst preparation (by successive impregnation or by co-impregnation of Mn and Pt) and Mn content in the catalyst performance has been studied. A low Mn content (2 wt.%) has been found not to improve the catalyst activity compared to the base catalyst. However, catalysts prepared by successive impregnation with 8 and 15 wt.% Mn have shown a lower operation temperature for maximum CO conversion than the base catalyst with an enhanced catalyst activity at low temperatures with respect to Pt/Al₂O₃. A maximum CO conversion of 89.8%, with selectivity of 44.9% and CO yield of 40.3% could be reached over a catalyst with 15 wt.% Mn operating at 139 °C and λ = 2. The effect of the presence of 5 vol.% CO₂ and 5 vol.% H₂O in the feedstream on catalysts performance has also been studied and discussed. The presence of CO₂ in the feedstream enhances the catalytic performance of all the studied catalysts at high temperature, whereas the presence of steam inhibits catalysts with higher MnO_x content.     

The reactions of ethanol over M/CeO2 catalysts: Evidence of carbon–carbon bond dissociation at low temperatures over Rh/CeO2

The reactions of ethanol over Rh/CeO₂ have been investigated using the techniques of temperature programmed desorption (TPD) and FT-IR spectroscopy, in addition to steady state catalytic tests. A comparison with previous studies of ethanol adsorption over Pd/CeO₂ [J. Catal. 186 (1999) 279] and Pt/CeO₂ [J. Catal. 191 (2000) 30] catalysts is presented. The apparent activation energy for the reaction was 49, 40, and 43 kJ mol⁻¹ for Rh/CeO₂, Pd/CeO₂ and Pt/CeO_2, respectively, while the turnover number (TON) at 400 K was 5.9, 8.6 and 2.6, respectively. Surface compositions of catalysts were characterised by XPS. A decrease of the atomic O(1s)/Ce(3d) ratio of the CeO₂ support indicates its partial reduction upon addition of the noble metal. The extent of reduction per metal atom was in the following order: Pt>Pd>Rh. FT-IR and TPD studies have shown that dehydrogenation of ethanol to acetaldehyde occurred over Pd/CeO₂, Pt/CeO₂ and Rh/CeO₂. Moreover, Rh/CeO₂ readily dissociated the C–C bond of ethanol at room temperature to form adsorbed CO (IR bands at 1904–2091 cm⁻¹). This was corroborated by the low desorption temperature of CH₄ over Rh/CeO₂ (450 K) when compared to that of Pd/CeO₂ (550 K) or Pt/CeO₂ (585 K).     

Nano-structured CeO2 supported Cu-Pd bimetallic catalysts for the oxygen-assisted water–gas-shift reaction

The present work focuses on the development of novel Cu-Pd bimetallic catalysts supported on nano-sized high-surface-area CeO₂ for the oxygen-assisted water–gas-shift (OWGS) reaction. High-surface-area CeO₂ was synthesized by urea gelation (UG) and template-assisted (TA) methods. The UG method offered CeO₂ with a BET surface area of about 215 m²/g, significantly higher than that of commercially available CeO₂. Cu and Pd were supported on CeO₂ synthesized by the UG and TA methods and their catalytic performance in the OWGS reaction was investigated systematically. Catalysts with about 30 wt% Cu and 1 wt% Pd were found to exhibit a maximum CO conversion close to 100%. The effect of metal loading method and the influence of CeO₂ support on the catalytic performance were also investigated. The results indicated that Cu and Pd loaded by incipient wetness impregnation (IWI) exhibited better performance than that prepared by deposition–precipitation (DP) method. The difference in the catalytic activity was related to the lower Cu surface concentration, better Cu–Ce and Pd–Ce interactions and improved reducibility of Cu and Pd in the IWI catalyst as determined by the X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) studies. A direct relation between BET surface area of the CeO₂ support and CO conversion was also observed. The Cu-Pd bimetallic catalysts supported on high-surface-area CeO₂ synthesized by UG method exhibited at least two-fold higher CO conversion than the commercial CeO₂ or that obtained by TA method. The catalyst retains about 100% CO conversion even under extremely high H₂ concentration.