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Your search keyword '"Peurla, Markus"' showing total 171 results
Start Over Author "Peurla, Markus" Publication Type Academic Journals
171 results on '"Peurla, Markus"'

23. Ti-MWW Catalysts for Propylene Oxide Production: Influence of Si/Ti Ratio and Calcination Conditions.

Author

Alvear, Matias, Schmidt, Christoph, Reinsdorf, Ole, Lebron-Rodrigez, Edgard, Al Abdulghani, Abdullah, Hermans, Ive, Peurla, Markus, Lastusaari, Mika, Eränen, Kari, Murzin, Dmitry Yu., Kumar, Narendra, and Salmi, Tapio

Subjects
PROPYLENE oxide, TITANIUM silicate, CATALYSTS, CATALYTIC activity, BORIC acid
Abstract

Titanium silicates of MWW structures with different Si/Ti ratios were prepared via hydrothermal synthesis using piperidine as the structure directing agent and boric acid as the crystallization agent. All the syntheses resulted in highly crystalline materials independent of the Si/Ti ratio. The observed morphology showed MWW-like well-defined thin hexagonal platelets. The synthesized Ti-MWW materials exhibited higher surface areas and partial meso-porosity compared to the commercial TS-1 catalyst. The coordination of the Ti-species was investigated by UV–vis- and IR-spectroscopy. The MWW titanium silicates were tested for the catalytic performance in the epoxidation of propylene in a laboratory-scale trickle bed reactor to compare their clear different physico-chemical properties with the commercial TS-1. The synthesized Ti-MWW materials showed significantly higher catalytic activities, up to 3.5 times, using acetonitrile as the solvent and enhanced epoxide selectivities partially up to 100% in methanol unlike TS-1. The effect of the Ti content in the MWW and the calcination conditions were investigated in propylene epoxidation, revealing the beneficial effect of a lower calcination temperature and an increased Ti content on the activity. The catalytic results were correlated with the physico-chemical properties of the synthesized materials. [ABSTRACT FROM AUTHOR]

Published
2024
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40. Interactions between Iron and Nickel in Fe–Ni Nanoparticles on Y Zeolite for Co-Processing of Fossil Feedstock with Lignin-Derived Isoeugenol.

Author

Vajglová, Zuzana, Gauli, Bibesh, Mäki-Arvela, Päivi, Kumar, Narendra, Eränen, Kari, Wärnå, Johan, Lassfolk, Robert, Simakova, Irina L., Prosvirin, Igor P., Peurla, Markus, Lindén, Johan Kaarle Mikael, Huhtinen, Hannu, Paturi, Petriina, Doronkin, Dmitry E., and Murzin, Dmitry Yu.

Abstract

A set of low-cost monometallic Fe, Ni, and bimetallic Fe–Ni bifunctional H–Y-5.1 catalysts with different metal ratios were synthesized by sequential incipient wetness impregnation. The catalysts were characterized in detail by N2 physisorption, Fourier transform infrared spectroscopy with pyridine, inductively coupled plasma optical emission spectroscopy, X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM–SEM), magic angle spinning nuclear magnetic resonance, X-ray photoelectron spectroscopy (XPS), Mössbauer spectroscopy, magnetic measurements, temperature-programmed reduction (TPR), and X-ray absorption spectroscopy (XAS). The results revealed that introduction of Fe led to a decrease of strong acid sites and an increase of medium Brønsted acid sites, while introduction of Ni increased the number of Lewis acid sites. The particle size of iron was approx. 5 nm, being ca. fourfold higher for nickel. XPS demonstrated higher iron content on the catalyst surface compared to nickel. Both Mössbauer spectroscopy and magnetic measurement confirmed the ferromagnetic behavior of all catalysts. In addition, the results from XRD, TEM, XPS, XAS, and magnetization suggested strong Fe–Ni nanoparticle interactions, which were supported by modeling of TPR profiles. Catalytic results of the co-processing of fossil feedstock with lignin-derived isoeugenol clearly showed that both product distribution and activity of Fe–Ni catalysts strongly depend on the metals' ratio and their interactions. Key properties affected by the Fe–Ni metal ratio, which played a positive role in co-processing, were a smaller medial metal nanoparticle size (<6 nm), a lower metal–acid site ratio, as well as presence in the catalyst of fcc FeNi alloy structure and fcc Ni doped with Fe. [ABSTRACT FROM AUTHOR]

Published
2023
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44. Small‐Molecule‐based Supramolecular Plastics Mediated by Liquid‐Liquid Phase Separation**.

Author

Yu, Jingjing, Qi, Dawei, Mäkilä, Ermei, Lassila, Lippo, Papageorgiou, Anastassios C., Peurla, Markus, Rosenholm, Jessica M., Zhao, Zhao, Vallittu, Pekka, Jalkanen, Sirpa, Jia, Chunman, and Li, Jianwei

Subjects
YOUNG'S modulus, SMALL molecules, PLASTICS, PHASE separation, COVALENT bonds, POLLUTION
Abstract

Plastics are one of the most widely used polymeric materials. However, they are often undegradable and non‐recyclable due to the very stable covalent bonds of macromolecules, causing environmental pollution and health problems. Here, we report that liquid‐liquid phase separation (LLPS) could drive the formation of robust, stable, and sustainable plastics using small molecules. The LLPS process could sequester and concentrate solutes, strengthen the non‐covalent association between molecules and produce a bulk material whose property was highly related to the encapsulated water amounts. It was a robust plastic with a remarkable Young's modulus of 139.5 MPa when the water content was low while became adhesive and could instantly self‐heal with more absorbed water. Finally, responsiveness enabled the material to be highly recyclable. This work allowed us to understand the LLPS at the molecular level and demonstrated that LLPS is a promising approach to exploring eco‐friendly supramolecular plastics that are potential substitutes for conventional polymers. [ABSTRACT FROM AUTHOR]

Published
2022
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46. Diffusion measurements of hydrocarbons in H-MCM-41 extrudates with pulsed-field gradient nuclear magnetic resonance spectroscopy.

Author

Zhivonitko, Vladimir V., Vajglová, Zuzana, Mäki-Arvela, Päivi, Kumar, Narendra, Peurla, Markus, Telkki, Ville-Veikko, and Murzin, Dmitry Yu.

Abstract

Mesoporous materials are promising catalysts for production of biofuels. Herein, H-MCM-41 catalysts with different concentrations of the silica Bindzil binder (10–50 wt%) were prepared and characterized using pulsed-field gradient (PFG) NMR in the powder form and as extrudates. Effective diffusion coefficients (De) are measured in all cases. Diffusivities of n-hexadecane were found smaller for extrudates as compared to the powder catalysts. The estimates of diffusive tortuosity were also determined. PFG NMR data showed one major component that reveals diffusion in interconnected meso- and micropores and one other minor component (1–2%) that may correspond to more isolated pores or may represent complex effects of restricted diffusion. Therefore, several approaches including initial slope analysis of spin-echo attenuation curves, two-component fitting and Laplace inversion were used to discuss different aspects of diffusional transport in the studied H-MCM-41 materials. Correlations between De and the amount of Bindzil, the specific surface area, the micropore volume, the particle size, the total acid sites and the Lewis acid sites are discussed. [ABSTRACT FROM AUTHOR]

Published
2022
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48. Deactivation and regeneration of Pt‐modified zeolite Beta–Bindzil extrudates in n‐hexane hydroisomerization.

Author

Vajglová, Zuzana, Kumar, Narendra, Peurla, Markus, Hupa, Leena, Semikin, Kirill, Sladkovskiy, Dmitry A, and Murzin, Dmitry Yu

Subjects
CATALYST poisoning, CHEMICAL processes, INDUSTRIAL chemistry, ZEOLITES, CHEMICAL industry, CATALYSTS
Abstract

BACKGROUND: The metal–acid bifunctional catalysts are widely used in many industrially significant chemical processes, including hydroisomerization of n‐hexane. Deactivation and regeneration of metal–acid bifunctional extrudates was investigated in continuous n‐hexane hydroisomerization in a fixed‐bed reactor. Four Pt/H‐Beta‐25 catalysts containing 30% Bindzil binder were prepared with the same composition and controlled metal deposition. RESULTS: Different preparation steps led to differences in the mechanical strength, Pt particle size, acidity and strength, metal‐to‐acid site (cPt/cAS) ratio and proximity between two types of active sites. A very slow deactivation and high selectivity to C6 isomers was obtained when Pt was deposited on H‐Beta‐25 zeolite. CONCLUSION: Initial selectivity to the desired products was correlated with the physicochemical properties of the catalysts. Location of the metal has a larger influence on catalyst deactivation of the bifunctional catalysts rather than the metal‐to‐acid site ratio or site proximity. Decline of n‐hexane conversion and selectivity to C6 isomers were correlated with changes in the textural properties and acidity of the deactivated catalyst, respectively. © 2021 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Published
2021
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