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ACS applied nano materials 6(12), 10064 - 10077 (2023). doi:10.1021/acsanm.3c00620, 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 N$_2$ 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 (, Published by ACS Publications, Washington, DC

In the microreactor, the 1,2-dichlorethane selectivities of 4.7% and 53.6% were achieved with the ethene conversions of 1.6% and 6.4%, respectively. The other important product was chloroethane. The formation of vinyl chloride by-product of 1.6% was observed only at the highest temperature 250 °C with highest ethene conversion achieved (6.4%). No other by-products were observed. In the millireactor, the 1,2-dichlorethane selectivities exceeding 96% were achieved at ethene conversions higher than 11% within the entire experimental range. Chloroethane, vinyl chloride, 1,2-dichloroethylene (trans) were formed, but only in minor amounts.

This contribution focuses on the induced oscillatory behaviour observed during the continuous hydrogenation of 2MP in a packed bed microreactor. Induced reproducible oscillations have been studied using the on-line gas chromatograph (GC-FID/TCD) and a catalyst bed temperature monitoring. Effects of the temperature, thermal conductivity and space velocity on the properties of induced oscillations have been investigated in detail. The study results revealed extremely high sensitivity of the oscillatory behaviour to the heat transfer conditions in the system. Experimental tests focusing on the space velocity effect revealed a significant influence on the oscillation amplitude height and period phase length with the high reaction rate. Based on the character of the induced oscillations, they have been classified as thermo-kinetic oscillations1 as they are resulting from the interaction between the exothermic reaction, heat transfer and a reversible decrease in the catalyst activity.

Aliphatic hydrocarbons with 4 – 5 carbon chain are very valuable starting materials for the steam cracking process. In terms of volume, the C4 and C5 fractions are the most important by-product streams from the pyrolysis of naphtha and other liquid raw materials. Total hydrogenation of C4 and C5 fraction is a way how to produce a high-quality raw material for pyrolysis, which in comparison with a simple recycle olefin (non-hydrogenated) fractions provides higher yields of ethylene and propylene and does not shorten the operating period of the pyrolysis furnaces by excessive coking1,2. For better understanding of the C4 fraction hydrogenating process, reaction kinetic study was performed in laboratory conditions. The hydrogenation of 2-methylpropene (isobutene) on platinum catalyst was investigated experimentally as a model reaction. The effort was focused on development of the methodology of kinetic data collection under the kinetic regime. To have a representative kinetic data, results reproducibility and process stability within several days on-stream was investigated.

This study focuses on hydrogenation of C4 fraction, more specifically on development of the methodology of kinetic data collection and evaluation. The hydrogenation of 2- methylpropene on platinum catalyst was investigated as a model reaction.

Analysis of the total oxidation of ethanol including reaction intermediates data obtained in the examined reactors on the temperature showed that differentmaterial applied in the construction of reactors and their arrangement give slightly different results of catalyst testing, the ones obtained from microreactor being more precise. More precise control of reaction temperature due to higher heat transfer capabilities and limited backmixing of reaction mixture in a packed bed microreactor is advantageous and leads to the more accurate results of oxidation catalysts testing. However, it is necessary to ensure in order the material used for the reactor construction did not affect the catalytic reaction. The results accomplished confirm that microreactors are not only suitable for performing of catalytic reactions in a laboratory scale but also promising way for creation of new, safer and cleaner production processes.

Most authors used for their studies of technical decaBDE mixture, or pure congener BDE 209. Very few studies used the technical octaBDE mixtures or pentaBDE, or congener BDE 47, which are most abundantly represented in the environment. Photodegradation of PBDE by catalysis over nanoporous TiO2 in microwave field showed very positive results. Debromination of BDE 209 after 240 minutes was very high and reached 99% (from initial value of 14 125 ng/mL). Lower brominated congeners including the tri brominated congener BDE 28 were safely determined.

In order to decrease the environmental impact of PBDE’s and to stop their spread in the food chain, the different degradation methods have been investigated. One of the relatively newly developed methods for the degradation of polybrominated diphenyl ethers is a method of electrochemical degradation. Electrochemically generated hydrogen atoms are more reactive, even under much milder conditions than the conventional method of reducing degradation of polybrominated diphenyl ethers.

This contribution presents results of the characterization of a new high-temperature high-pressure integrated packed-bed microreactor (MCTU 600 from Ehrfeld Mikrotechnik BTS GmbH) for lab-scale catalyst testing. As the model reaction we used the hydrogenation of C4-C5 aliphatic alkenes heterogeneously catalyzed by Pt/Al2O3 or Pd/Al2O3.