M. D. Smolikov, V. A. Shkurenok, S. S. Yablokova, K. V. Kazantsev, T. I. Gulyaeva, I. V. Muromtsev, A. V. Lavrenov
{"title":"Porous Alumina-Supported Tungstated Zirconia Catalysts for Heptane Isomerization","authors":"M. D. Smolikov, V. A. Shkurenok, S. S. Yablokova, K. V. Kazantsev, T. I. Gulyaeva, I. V. Muromtsev, A. V. Lavrenov","doi":"10.1134/s207005042470003x","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Novel WO<sub>3</sub>–ZrO<sub>2</sub> (WZ) catalysts with palladium as an active metal on porous alumina supports of various phase compositions have been synthesized. Aluminas from Sasol molded in the form of extrudates (E) and spherical aluminas (S), in which the phase composition is presented by θ-Al<sub>2</sub>O<sub>3</sub>, δ-Al<sub>2</sub>O<sub>3</sub>, and α-Al<sub>2</sub>O<sub>3</sub> alumina, have been used as supports. It has been shown that the phase composition of the support has a significant effect on the activity of supported Pd/WZ catalysts based on it. Upon transition from a set of θ- and δ-Al<sub>2</sub>O<sub>3</sub> phases to the θ- and α-Al<sub>2</sub>O<sub>3</sub> phase composition has led to an increase in the activity of the catalysts, as evidenced by a shift of 10–30°C in the temperature dependences of the heptane conversion to lower temperatures. The appearance of the α-Al<sub>2</sub>O<sub>3</sub> phase is accompanied by a decrease in the specific surface area of the catalysts, which leads to an increase in the density of acid sites and, as a consequence, a change in activity. The Pd/WZ catalysts supported on S aluminas are characterized by a higher acidity (3.7–6.3 μmol/m<sup>2</sup>) as compared to the samples supported on E aluminas (2.8–3.6 µmol/m<sup>2</sup>). The high acidity of the Pd/WZ/S catalysts intensifies the heptane cracking side reactions to form gaseous C<sub>1</sub>–C<sub>4</sub> hydrocarbons. In turn, the moderate acidity of the Pd/WZ/E catalysts contributes to a higher selectivity to heptane isomers (89.2–89.3% at a heptane conversion of 81.5–83.2%) as compared to the catalysts supported on S supports (isomerization selectivity of 84.9–85.6% at a heptane conversion of 80.4–81.4%).</p>","PeriodicalId":507,"journal":{"name":"Catalysis in Industry","volume":null,"pages":null},"PeriodicalIF":0.7000,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catalysis in Industry","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1134/s207005042470003x","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Novel WO3–ZrO2 (WZ) catalysts with palladium as an active metal on porous alumina supports of various phase compositions have been synthesized. Aluminas from Sasol molded in the form of extrudates (E) and spherical aluminas (S), in which the phase composition is presented by θ-Al2O3, δ-Al2O3, and α-Al2O3 alumina, have been used as supports. It has been shown that the phase composition of the support has a significant effect on the activity of supported Pd/WZ catalysts based on it. Upon transition from a set of θ- and δ-Al2O3 phases to the θ- and α-Al2O3 phase composition has led to an increase in the activity of the catalysts, as evidenced by a shift of 10–30°C in the temperature dependences of the heptane conversion to lower temperatures. The appearance of the α-Al2O3 phase is accompanied by a decrease in the specific surface area of the catalysts, which leads to an increase in the density of acid sites and, as a consequence, a change in activity. The Pd/WZ catalysts supported on S aluminas are characterized by a higher acidity (3.7–6.3 μmol/m2) as compared to the samples supported on E aluminas (2.8–3.6 µmol/m2). The high acidity of the Pd/WZ/S catalysts intensifies the heptane cracking side reactions to form gaseous C1–C4 hydrocarbons. In turn, the moderate acidity of the Pd/WZ/E catalysts contributes to a higher selectivity to heptane isomers (89.2–89.3% at a heptane conversion of 81.5–83.2%) as compared to the catalysts supported on S supports (isomerization selectivity of 84.9–85.6% at a heptane conversion of 80.4–81.4%).
期刊介绍：
The journal covers the following topical areas:
Analysis of specific industrial catalytic processes: Production and use of catalysts in branches of industry: chemical, petrochemical, oil-refining, pharmaceutical, organic synthesis, fuel-energetic industries, environment protection, biocatalysis; technology of industrial catalytic processes (generalization of practical experience, improvements, and modernization); technology of catalysts production, raw materials and equipment; control of catalysts quality; starting, reduction, passivation, discharge, storage of catalysts; catalytic reactors.Theoretical foundations of industrial catalysis and technologies: Research, studies, and concepts : search for and development of new catalysts and new types of supports, formation of active components, and mechanochemistry in catalysis; comprehensive studies of work-out catalysts and analysis of deactivation mechanisms; studies of the catalytic process at different scale levels (laboratory, pilot plant, industrial); kinetics of industrial and newly developed catalytic processes and development of kinetic models; nonlinear dynamics and nonlinear phenomena in catalysis: multiplicity of stationary states, stepwise changes in regimes, etc. Advances in catalysis: Catalysis and gas chemistry; catalysis and new energy technologies; biocatalysis; nanocatalysis; catalysis and new construction materials.History of the development of industrial catalysis.
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