Search

Introduction (page 1) ‘The scenario dramatically changed as Haruta et al. (1985) and Hutchings (1987)’. SHOULD BE ‘The scenario dramatically changed as Haruta et al. (1987) and Hutchings (1985)’. Notation [Table presented]SHOULD BE [Table presented] References The following references are missing in the reference list at the end of the article: Haruta, M., Kobayashi, T., Hiroshi, S., Nobumasa, Y., 1987. Novel Gold Catalysts for the Oxidation of Carbon Monoxide at a Temperature far below 0 °C. Chem. Lett. 16, 405–408. Hutchings, J.H., 1985. Vapor phase Hydroclorination of Acetylene: Correlation of Catalytic Activity of Supported Metal Chloride Syntesis. J. Catal. 96, 292–295.

This work describes an effective method for the preparation of open-cell ceramic foams for their further use as catalyst supports. The polyurethane sponge replica technique was applied using a ceramic suspension based on a mixture of α-alumina, magnesia and titania and polyvinyl alcohol solution as a liquid component. The polyurethane sponge was etched with NaOH and covered with colloidal silica to obtain better adhesion of the slurry to the walls of the polymeric material onto it. The surface area of the ceramic carrier was increased by adding a layer of γ-alumina. Deposition of an active catalytic phase (Pt) was done by impregnation. Properties of the carriers and the final catalyst were investigated by a number of physico-chemical methods such as TEM, SEM, XRD and computer tomography. Hydrogenation of ethyl benzoylformate was performed to elucidate the catalytic properties of foam catalysts illustrating their applicability.

Tuning the morphology of heterogeneous catalysts is of paramount importance for the design of efficient processes and requires detailed information on the physicochemical characteristics of the materials. Four micro-/mesoporous composites with different morphologies were synthesized by a dual-templating method using two-step crystallization with different zeolite seed concentrations. This work demonstrates the dependence of selectivity on the catalyst nature in solid-acid alkylation. It was demonstrated that a high concentration of weak acid sites leads to dialkyltoluene products, whereas a high concentration of strong acid sites is beneficial for other side reactions. It was shown that the morphology of catalysts played a crucial role in solid-acid alkylation. The alkylation mechanism defined in this study with different contributions of weak and strong acid sites could provide a route to the development of effective solid-acid catalysts.

The carboxymethylation of cinnamylalcohol with dimethyl carbonate was performed using low-cost catalysts obtained from desulfurization slag. Processing of steel slag performed by different techniques was resulted in a wide range of the catalysts with different morphological and structural properties. Catalytic evaluation of the slag catalysts illustrated diversity of the obtained results strongly dependent on the surface area, crystal morphology and basicity. Catalytic materials demonstrated high variability of the conversion (8–85%) exhibiting similar selectivity to the desired product – cinnamyl methyl carbonate (ca. 80%). A significant impact of ultrasonication on catalytic activity was observed. Comparison of the synthesized samples with commercial basic materials illustrated competitive ability of the slag catalysts. Based on the results of catalytic evaluation and product analysis the reaction network was proposed and verified by thermodynamic analysis. A kinetic model was developed to describe concentration dependencies in carboxymethylation.

Kinetics of guaiacol hydrodeoxygenation (HDO) was studied using supported MoxC–SBA-15 and as a comparison 5 wt% Pt/C under 30 bar hydrogen at 200 °C and 300 °C. Catalyst characterization was done by a range of physical methods including also determination of the amount of coke and the nature of adsorbed species. Pt/C gave 2-methoxycyclohexanol as the main product, whereas Mo2C–SBA-15 promoted direct deoxygenation exhibiting also strong adsorption of guaiacol on the catalyst surface and formation of oligomers. Thermodynamics of guaiacol HDO was elucidated and the reaction network was proposed based on which kinetic modelling was done. Graphic Abstract: [Figure not available: see fulltext.]

Transformations of glucose to 1,2-propylene glycol were studied over a mechanical mixture of ZnO and Ru/C catalysts in the presence of hydrogen. Different reaction conditions were evaluated by changing the reaction temperature and hydrogen pressure. In addition to the cascade mode of operation, also separate steps in the overall reaction network, such as hydrogenation of pyruvaldehyde and hydroxyacetone to 1,2-propylene glycol were investigated. Fructose as a starting material was also studied resulting in a propylene glycol yield of 37.5%. The optimal temperature for glucose transformation to propylene glycol was found to be 165 °C. The influence of temperature on the catalytic behavior was more prominent than the effect of hydrogen pressure. Thermodynamic analysis of glucose transformation to 1,2-propylene glycol was performed and a plausible kinetic model reflecting a complex reaction network was developed being able to describe the data in a reliable way.