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The appearance of twin/stacking faults in nanoparticles creates strains affecting the catalytic, optical, and electrical properties of nanomaterials.

We deliver spectroscopic IR data describing the adsorption phenomena accompanying reduction of conjugated carbonyl compounds aided by heterogeneous catalysts.

CuO/ceria and CuO/Y-doped ceria catalysts were synthesized. The Y-modified supports (1.0, 2.5 and 5.0 wt% Y2O3) were prepared by coprecipitation. CuO (3 wt% Cu) was loaded by deposition-precipitation. Having in mind the known effect of Y3+ modification for the generation of oxygen vacancies in ceria, its positive role on the water-gas shift (WGS) performance was expected. However, the catalytic test showed a trend of decreased WGS activity by increasing the Y-dopant amount, nevertheless that the differences were not very substantial. On the basis of XRD, XPS, EPR, Raman spectroscopy and H2-TPR results the explanation related to the key role of the oxygen mobility influenced by Y-doping could be proposed. The reason of the inferior WGS performance with increasing Y-content would be the higher amount of surface oxygen vacancies around Y3+ ions which disturbed the Cu–Ovac–Ce active sites for WGS reaction. Though, during the long run catalytic tests in WGS reaction a positive effect of Y-doping for improved stability of CuO/ceria catalysts was evidenced.

The demands for high-purity hydrogen required in fuel-cell applications impose new goals and challenges for design of well performing water-gas shift (WGS) catalysts. Gold-based catalysts have exhibited high activity in the WGS reaction at low temperature. Preparation of appropriate and economically viable supports with complex composition by various synthesis procedures is an attractive approach to WGS performance improvement. The effect of two different preparation methods (wet impregnation or mechanical mixing) and ceria content (10, 20 or 30 wt%) on textural, structural, surface and reductive properties and WGS activity of gold catalysts was studied. Additionally, the role of Y2O3 as a promoter of ceria was examined. Long-term stability test was carried out at 260 °C over the most active catalyst. The composition of the best performing sample (composed of about 70 wt% alumina), prepared by mechanical mixing, was considered promising in case of practical applications because of its cost efficiency. The combination of gold nanoparticles and alumina supported Y-doped ceria proved an advantageous approach for developing new catalytic formulations with high effectiveness in clean hydrogen production.

Our research focuses on phenomena accompanying adsorption of mesityl oxide (4-methylpent-3-en-2-one) on the surface of heterogeneous supported gold catalysts: Au/CeO

Gold catalysts on Y-doped ceria dispersed on high surface area ?-Al2O3 were synthesized and tested in preferential CO oxidation in hydrogen rich stream (PROX). The effect of ceria loading (10, 20 or 30 wt%) was studied. The gold catalyst with the lowest ceria amount exhibited the highest PROX activity. The addition of Y2O3 (1 wt%) led to improved performance. The most favorable effect was observed in the sample with 20 wt% ceria amount. This gold catalyst showed good PROX activity and stability in the presence of CO2 and water. Catalysts characterization by XRD, HRTEM/HAADF, XPS and H2-TPR was used to elucidate the relationship between the chemical composition, state of gold, support features and catalytic properties.object Object]

The synthesis of catalytically active bimetallic Au–Pd nanoparticles stabilized in hyper-cross-linked polystyrene (HPS) for Suzuki cross-coupling of 4-bromoanisole (4-BrAn) and phenylboronic acid is presented. The core–shell structure with a thin (less than 1 nm) Pd shell and a Au core was proven by X-ray diffraction and high-angle annular dark-field scanning transmission electron microscopy combined with energy-dispersive X-ray spectroscopy. More than a 2-fold increase in 4-BrAn conversion was found in comparison with monometallic Pd/HPS. Moreover, when the Suzuki reaction was carried out under visible-light irradiation, the product yield further increased by about 1.3 times (from 56.1% up to 73.7%). This effect was assigned to a local surface plasmon resonance arising in the Au core that allowed electron transfer to the extremely thin Pd layer due to intimate contact with gold. The results suggest that the rate-limiting step of the catalytic cycle takes place on the surface of the Pd shell, serving as e...

The research presented in this paper addresses the question: How does the addition of a small amount of LaCoO3 impact the activity of a Co3O4 catalyst? By testing such a catalyst in N2O decomposition under conditions at which the thermal decomposition of Co3O4 to CoO is possible, one gains unique insight into how the two phases interact. The activity of such a catalyst increases in the entire studied temperature range, unlike the activity of the undoped cobalt catalyst which is lower at 850 °C than at 800 °C due to the reduction of Co3O4 to CoO. XRD measurements showed that CoO was also the main cobalt oxide present in the Co3.5La catalyst after operating at 850 °C, as did the XPS measurements, but there was no drop of activity associated with this change. The influence of NO, O2 and H2O on the activity of the new catalyst, Co3.5La, was determined. Lack of positive effect of NO, a known oxygen scavenger, on the activity was noticed at all temperatures, showing that the effect of LaCoO3 is probably due to increased oxygen desorption. Temperature programed oxidation (TPO) tests showed that the beneficial effects of the presence of LaCoO3 on the activity of cobalt oxide at 850 °C were probably caused by enhanced diffusion of O2− anions through the entire catalyst, which facilitates desorption of oxygen molecules from the surface.

We present an efficient strategy for synthesising the PdAu catalysts with a homogeneous PdAu alloy phase for environmentally important hydrodechlorination of tetrachloromethane in the gas phase. The synthesis of carbon-supported catalysts involved two major steps: (i) incorporation of palladium and gold nanoparticles into carbon support and (ii) activation of the catalysts. The critical part of this work was to find the optimal conditions for both steps. Thus, the incorporation of the nanoparticles was carried out in two ways, by impregnation and direct redox reaction method using acetone solutions of metal precursor salts. The activation was performed either by a conventional thermal reduction in hydrogen or flash irradiation in a microwave oven. The homogeneity and structure of the PdAu alloy were found to depend on the catalyst activation method critically. In all cases, we observed better homogeneity for catalysts that were subject to microwave irradiation. Moreover, the flash microwave irradiation of prepared catalysts provided catalysts of better stability and selectivity towards the desired products (hydrocarbons) in the hydrodechlorination of tetrachloromethane as compared to the catalyst obtained by conventional thermal activation in hydrogen.

Herein, the activity of Ag and bimetallic Au-Ag catalysts, supported over Ce0.85Zr0.15O2 (CZ), was investigated in a complex stream, whose components included CO, C3H8, NO, O2, and, optionally, an injection of water vapor. In such a stream, three of the possible reactions that can occur are CO oxidation, propane combustion, and NO oxidation. The aim of these studies was to explore whether silver, due to its strong affinity to oxygen, will counteract the stabilization of oxygen by potassium. The effect of the presence of potassium ions on the activity of the monometallic silver catalysts is beneficial in the complex stream without water vapor in all three studied reactions, although it is negligible in the model CO stream. It has been shown that water vapor strongly suppresses the activity of the Ag+K/CZ catalyst, much more so than that of the Ag/CZ catalyst. The second purpose of the work was to determine whether the negative effect of potassium ions on the activity of nanogold catalyst can be countered by the addition of silver. Studies in a model stream for CO oxidation have shown that, for a catalyst preloaded with gold, the effect of potassium is nulled by silver, and the activity of AuAg + 0.15 at%K/CZ and AuAg + 0.30 at%K/CZ is the same as that of the monometallic Au catalyst. Conversely, when the reaction is carried out in a complex stream, containing CO, C3H8, NO, O2, and water vapor, the presence of water vapor leads to higher CO conversion as well as increased NO2 formation and slightly suppresses the C3H8 combustion.

Organic-inorganic hybrid system composed of bimetallic Au@Pt nanoparticles with diameter of a few nanometers uniformly dispersed in the conducting polymer matrix was synthesized by a simple electrochemical/chemical method on glassy carbon electrode. The elaborated catalyst demonstrates an enhanced specific catalytic activity (9.7 A mg −1 Pt) in electrooxidation of formic acid. The reason of this improved performance is discussed in terms of the polymer structure used as the matrix for bimetallic catalyst and mechanism of formation of Au@Pt nanoparticles. Electrocatalytic activity of the hybrid systems obtained by means of two different procedures are compared to understand better the influence of the synthesis conditions on the properties of the catalyst. The composites are characterized by means HR-TEM, X-ray diffraction and X-ray fluorescence methods. Arrangement of nanoparticles in Au@Pt composite is determined by EDX elemental mapping. A new method of preparation of the samples embedded in thin polymer film for XRD and XRF measurements is proposed.

The reducibility of Au catalysts on CeO2 supports doped with 1 and 2.5 mass% Y2O3 by two types of preparation methods (impregnation and co-precipitation) has been studied by temperature-programmed reduction and compared with that of pure Au/CeO2. The kinetic parameters of reduction were determined simulating each reduction process. The capacities of these catalysts to retain oxygen have been evaluated by temperature-programmed desorption. The catalytic activities in water gas shift reaction were determined measuring CO conversion between 413 and 623 K. The catalytic performances of all these catalysts were explained in terms of mobility of the oxygen ions of the CeO2 lattice.

A method to analytically calculate the column length distribution (CLD) from a single reflection of a strain-free nanocrystalline metal is proposed. It involves precise estimation of the peak background level using a physical criterion – the positivity of the CLD. The method can be applied to materials showing a dependence of the lattice constant on the crystal size, because of which the diffraction peaks display asymmetry. The analysis can provide an estimation of this dependence. Results for platinum and gold nanocrystals are presented, showing and explaining the different asymmetry of their peaks. By applying the proposed method to diffraction patterns ofin situtreated gold nanocrystals, it is shown that the nanocrystal shape changes in response to changing environment.

Gold catalysts on CeO/AlO and Y-doped CeO/AlO supports (20 wt.% CeO and 1 wt.% YO) were synthesized. The mixed oxide supports were prepared by impregnation (IM) or by mechanical mixing (MM). The samples were characterised by BET, XRD and HRTEM/HAADF measurements. The catalytic properties in the preferential CO oxidation in hydrogen rich stream (PROX) using gas feed composition: 60% H+ 1% CO + 1% O (He as balance) were estimated. The effect of supports preparation on the gold loading and its dispersion, supports features and catalytic performance was commented. The positive effect of yttrium for catalysts stability was evidenced during long run tests in PROX with CO and water addition to gas stream. The obtained results could be useful for the design of catalysts for CO-free hydrogen production with good PROX performance at reasonable price.

Engineering the chemical composition of inorganic-organic hybrid perovskite materials is an effective strategy to boost the performance and operational stability of perovskite solar cells (PSCs). Among the diverse family of ABX(3) perovskites, methylammonium-free mixed A-site cation Cs(x)FA(1-x)PbI(3) perovskites appear as attractive light-absorber materials because of their optimum band gap, superior optoelectronic property, and good thermal stability. Here, we develop a simple and very effective one-step solution method for the preparation of high-quality (Cs)(x)(FA)(1-x)PbI3 perovskite films upon the addition of excess CsCl to the FAPbI(3) precursor solution. It is found that the addition of CsCl as a source of Cs cation instead of relevant addition of CsI to the parent perovskite solution increases effectively the grain size and film quality leading to improved charge mobility, reduced carrier recombination, and long carrier lifetime. The resultant mesoscopic perovskite devices exhibit a maximum efficiency of 20.60% with a stabilized power conversion efficiency of 19.85% and lower hysteresis compared to the reference device. This performance is among the highest reported for PSC devices incorporating mixed cation (Cs)(x)(FA)(1-x)PbI3 perovskites.

The utilization of pure hydrogen as an energy source in fuel cells gave rise to renewed interest in developing active and stable water-gas shift catalysts. Gold catalysts have proven to be very efficient for water-gas shift reaction at low temperature. The aim of the present study was to investigate the effect of: (i) different preparation methods (impregnation and coprecipitation) to obtain a modified ceria support, and (ii) the amount of Y2O3 (1.0 wt%, 2.5 wt%, 5.0 wt% and 7.5 wt%) as dopant on the water-gas shift activity of Au/CeO2 catalysts. An extended characterization by means of SBET, XRD, HRTEM/HAADF, FTIR, H2-TPR and CO-TPR measurements in combination with careful evaluation of the catalyst behavior allowed to shed light on the parameters governing the water-gas shift activity. The catalysts show very high activity (>90% CO conversion) in the temperature range 180–220 °C, with a slightly better performance of the gold catalysts on supports prepared by impregnation. The decreased activity with increasing Y2O3 concentration is related to the hindering of oxygen mobility due to ordering of surface oxygen vacancies in vicinity of segregated Y3+. The effect of catalyst pre-treatments and the stability of the best performing samples were examined as well.

Gold catalysts on CeO2/Al2O3 and Y-doped CeO2/Al2O3 supports prepared by mechanical mixing were tested in the preferential CO oxidation in hydrogen rich stream (PROX). The samples were characterised by XRD, HRTEM/HAADF, XPS and TPR measurements and the effect of preparation method on the textural, structural, reductive and catalytic properties was commented. The difference in the catalytic behaviour at the temperatures of interest for fuel cells application (80–120 °C) was not very substantial showing a degree of CO conversion in the range of 60 and 70%. An exception was the highest CO conversion at 80 °C observed over the gold catalyst on CeO2/Al2O3 with 20 wt.% ceria loading. The explanation of the lower activity of gold catalyst on Y-doped CeO2/Al2O3 with the same ceria amount was related to gold dispersion as a key factor for CO oxidation. The positive effect of yttrium was evidenced during long run tests in PROX with CO2 and water addition to gas stream. The better stability caused by the Y-presence was in agreement with the CO2-TPD results showing lower surface basicity.

The use of CCl4 as an effective medium to generate important phase changes in supported Pd and Au catalysts is presented. The dissolution of carbon that originates from CCl4 to form a PdC0.13 solid solution is more complete for the lowest temperature of the CCl4+H2 reaction (30–50 °C). At higher temperatures, the bulk carbiding competes with the hydrogenative removal of bare carbon species to contribute to an enhanced CH4 and C2H6 formation.

The preferential CO oxidation in the presence of excess hydrogen (PROX) was studied over gold catalysts on yttrium-modified ceria supports synthesized by impregnation (IM) and co-precipitation (CP) methods. In order to avoid oxygen vacancies ordering by heavily yttrium doping, a low extent Y-modification of ceria (up to 7.5 wt.% Y2O3, i.e., 11 at.% Y) was investigated. The samples were characterized by XRD, HRTEM/HAADF, Raman and XP spectroscopy and TPR measurements. At the operating temperature of the fuel cells (80-120 degrees C) the selectivity of the Y-doped gold catalysts was larger than that of Au/CeO2. However, at these temperatures all studied catalysts exhibited quite similar PROX activity and selectivity. This was explained by the similarity in relatively small average size of gold particles (estimated by HRTEM in the 2.1-3.5 nm range) and the reducibility of ceria surface layers. Raman spectroscopy showed a higher extent of bulk defects, O vacancies and interstitials with increasing Y-doping in the supports made by the CP method and-based on sequential spectra obtained under oxidizing and reducing conditions-enabled the assignment of a band at similar to 605 cm(-1) to a vibrational mode within the anionic (oxygen) sub-lattice that involve mobile (detachable) oxygen atoms that can be delivered by the support under suitable conditions. The absence of correlation between CO conversion and yttrium loading could suggest a preferential role played by the surface modification and surface oxygen mobility in PROX. Although under ideal conditions there was not substantial dependence of the behavior in PROX on the preparation method of doped supports, the IM method was more appropriate than the CP method for PROX with CO2 and water addition to the gas feed. The improved tolerance to CO2 could be explained by the lowering of ceria surface basicity due to the nanosized Y2O3, covering ceria grains. (C) 2016 Elsevier B.V. All rights reserved.

The purpose of the study was to show how a controlled, subtle change of the reducibility of the support by deposition of potassium ions impacts the activity of gold catalysts. Since the activity of supported gold catalysts in carbon monoxide oxidation is known to strongly depend on the reducibility of the support, this reaction was chosen as the model reaction. The results of tests conducted in a simple system in which the only reagents were CO and O2 showed good agreement with the CO activity trend in tests performed in a complex stream of reagents, which also contained CH4, C2H6, C3H8, NO, and water vapor. The results of the X-ray Diffraction (XRD) studies revealed that the support has the composition Ce0.85Zr0.15O2, that its lattice constant is the same for all samples, and that gold is mostly present in the metallic phase. The reducibility of the systems was established based on Temperature Programmed Reduction (TPR) and in situ XRD measurements in H2 atmosphere. The results show that the low temperature reduction peak, which is due to the presence of gold, is shifted to a higher value by the presence of 0.3 at% potassium ions on the surface. Moreover, the increase of the potassium loading leads to a more pronounced shift. The T50 of CO oxidation in the simple model stream was found to exhibit an excellent linear correlation with the maximum temperature of the low temperature reduction peak of Au catalysts. This means that stabilizing oxygen with a known amount of potassium ions can be numerically used to estimate the T50 in CO oxidation. The results in the complex stream also showed a similar dependence of CO conversion on reducibility, though there was no substantial difference in the activity of the catalysts in other reactions regardless of the potassium loading. These studies have shown that the influence of potassium varies depending on the reaction, which highlights differences in the impact of reducibility and importance of other factors in these reactions.

Mono metallic and bimetallic Pd (1 wt. %)&ndash, Au (3 wt. %) catalysts were prepared using two ceria supports doped with 1 wt. % Y2O3. Yttrium was added by impregnation or co-precipitation. The catalyst synthesis was carried out by deposition&ndash, precipitation method, with sequential deposition&ndash, precipitation of palladium over previously loaded gold in the case of the bimetallic samples. The obtained materials, characterized by X-ray powder diffraction (XRD), High resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and temperature programmed reduction (TPR) techniques, were tested in the complete benzene oxidation (CBO). The results of the characterization analyses and the catalytic performance pointed to a close relationship between structural, redox, and catalytic properties of mono and bimetallic catalysts. Among the monometallic systems, Pd catalysts were more active as compared to the corresponding Au catalysts. The bimetallic systems exhibited the best combustion activity. In particular, over Pd&ndash, Au supported on Y-impregnated ceria, 100% of benzene conversion towards total oxidation at the temperature of 150 &deg, C was obtained. Comparison of surface sensitive XPS results of fresh and spent catalysts ascertained the redox character of the reaction.

The WGS activity of gold catalysts on ceria doped with Pr (5 and 10 at% Pr) was studied. The supports were synthesized by impregnation (IM) and microemulsion (ME) method. Gold (3 wt%) was introduced by deposition-precipitation method. The samples were characterized by means of XRD, TEM, XPS and TPR measurements. The catalytic activity in WGSR of fresh catalysts did not differ significantly. After re-oxidation following the first catalytic run, the activity of gold catalyst on IM support with 5 at% Pr increased, while a significant drop in activity of the gold catalyst on ME support containing 10 at% Pr was registered. In the latter case the presence of very small gold particles were responsible for the initial WGS activity, while their agglomeration after the catalytic reaction caused the observed activity decrease. In the former case the higher activity during the second catalytic run could be explained by: (i) the redox behavior, showing that only in this case the most mobile oxygen could be fully recovered; (ii) the morphology of the support, revealing better crystallization of the support after WGS catalytic test as compared to the presence of partially amorphous ceria in the fresh gold catalyst.

Atoms at the surface of nanocrystals contribute appreciably to the X-ray diffraction pattern. Phenomena like chemisorption, affecting the displacement of surface atoms with respect to their positions in the perfect crystallographic structure, cause diffraction peak shifts and intensity changes. These effects are easily measurable for small nanocrystals up to 10 nm size. This article reports diffraction effects of chemisorption of adsorbing gases H2, O2, CO and NO for a series ofin situpowder diffraction experiments on nanocrystalline Pt supported on silica. On the basis of previous diffraction observation of Pt surface reconstruction during hydrogen desorption, it was possible to quantify this effectversuscrystallite size and rationalize the observed diffraction peak shift for the other adsorbing species. This enabled the surface reconstruction to be distinguished from the surface relaxation effect, the latter depending monotonically on the adsorption energy. Even if no phase transition occurs, monitoring of a peak's position, intensity, width and gas composition (viamass spectrometry) during a carefully designed physicochemical process (including surface chemical reaction) enables insight into and understanding of the surface structure evolution (e.g.amorphization, relaxation, reconstruction or changes in the overall morphology). The proposed technique can be used as a surface science tool, allowing studies of nanocrystals under high pressure.

Two series of Pr-doped (5 and 10 at.% Pr) cerium oxides were synthesized by impregnation (IM) and microemulsion method (ME). The Au catalysts (3 wt.%) supported on these oxides were tested in PROX. The samples were characterized by XRD, XPS and TPR measurements. At the operating temperature of the fuel cells (80–120 °C) gold catalysts on Pr-doped ceria supports synthesized by IM method exhibited much higher PROX activity as compared to the case of ME method. The observed different catalytic behavior was attributed to the different support preparation affecting the gold particle sizes and the mixed support features. In the case of mixed supports synthesized by IM the size of gold particles established by XRD is smaller and the supply of oxygen evidenced by the obtained TPR results is higher as compared to the gold catalysts on the ME prepared mixed supports. The higher gold dispersion as well as the more defective structure assumed by higher microstrain parameter of ceria lattice (XRD data) due to Pr-doping by IM method, improved both the reducibility and the PROX activity up to 120 °C.

Electrodes modified with oppositely charged platinum and gold nanoparticles exhibit electrocatalytic synergy of glucose oxidation. Such a simple method of preparation of bimetallic nanoparticulate films produces an electrode with significant shift of the onset potential as compared to electrodes prepared only from platinum (ca. 0.45 V) or gold (ca. 0.6 V) nanoparticles. The observed effect results from close proximity of the Au and Pt nanoparticles surfaces within the film. The electrode was also characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, powder X-ray diffraction measurements and cyclic voltammetry.

We report an operando XRD/MS experiment on nanocrystalline Pt supported on silica, monitoring quick growth of Pt in an NO atmosphere. XRD data following NO flow show structural changes typical of surface reconstruction. Although a small pressure of NO lifts surface reconstruction of a clean surface, a higher pressure of NO causes the surface to reconstruct again. TEM photographs show formation of clusters of Pt nanoparticles, pointing to growth controlled by coalescence. As surface reconstruction is the phenomenon that we always see accompanying quick growth, we postulate a mechanism of self-lifting cyclic reconstruction that drives the transport of whole clusters and their fusion.

a b s t r a c t Gold catalysts supported on ceria doped by different metal oxides (Me = Fe, Mn, Sn) were synthesized by two different methods: coprecipitation (CP) and mechanochemical activation (MA). Samples were characterized by means of XRD, HRTEM, TPR and XPS. Both XRD and HRTEM analyses reveal differences in the average size of the gold and ceria particles. As shown by TPR data, ceria doping improves oxygen mobility, i.e. a higher oxygen capacity was observed while compared with gold catalyst on undoped ceria. The method of preparation and the nature of dopant applied influence the catalytic performance in the water-gas shift (WGS) reaction. The differences in WGS activity between the MA and CP samples were significant. The MA catalysts, doped by Fe and Mn, manifested higher WGS activity than the undoped Au/ceria sample and the sample doped by Sn. A high concentration of Ce3+ ions in the highly active catalysts containing Fe or Mn was registered by XPS and found consistent with an earlier proposed model of the active sites for the WGS reaction.

The effect of potassium on CO disproportionation on Ni/Al 2 O 3 catalyst was studied. The examinations showed that small potassium content, below 1.5 mol%, does not affect the reaction rate while large potassium content, 6.0 mol%, slightly hinders the reaction. Carbon deposits produced during the disproportionation were studied by TP hydrogenation method. The measurements showed that: (i) the deposit formed on unpromoted sample is easy to hydrogenate and consists of adsorbed carbon atoms while (ii) the deposits formed on potassium promoted samples are difficult to hydrogenate and consist of co-adsorbed C atoms and CO molecules, being in intimate contact with potassium.

Gold (3 wt. %) catalysts on Y-doped (1, 2.5, 5 and 7.5 wt. % Y2O3) ceria supports prepared by coprecipitation (CP) or impregnation (IM) were studied in complete benzene oxidation (CBO). A low-extent Y modification was chosen to avoid ordering of oxygen vacancies. The samples were characterized by XRD, TGA, XPS and TPR techniques. A positive role of air pretreatment at 350 °C as compared to 200 °C was established for all Y-containing catalysts and it was explained by cleaning the active sites from carbonates. The oxygen supply cannot be considered as a limiting step for benzene oxidation except for the high 7.5%-doped samples, as suggested by TGA and TPR data. On the basis of XPS results of fresh and used in CBO catalysts, the presence of cationic gold species does not seem important for high CBO activity. The gold catalyst on an IM support with 1% Y-doping exhibited the best performance. A 100% benzene conversion was achieved only over this catalyst and Au/ceria, while it was not reached even at 300 °C over all other studied catalysts. Gold and ceria particle agglomeration or coke formation should be excluded as a possible reason, and the most probable explanation could be associated with the importance of the benzene activation stage.