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Hydrodeoxygenation (HDO) of isoeugenol was carried out at 200 °C and 30 bar of H2 in a batch reactor using a series of bifunctional catalysts consisting of platinum supported on zeolite H-Beta-25 or H-Beta-300 and Bindzil as a binder. The purpose of the matrix was to understand the effect of the binder on the reaction, emulating the components of industrial catalysts and therefore facilitating catalyst scale-up. The effect of the supports acid strength, the location of metal nanoparticles, and their proximity to acid sites was also studied. The catalysts were characterized by N2 physisorption, inductively coupled plasma atomic emission spectrometry, Fourier transform infrared spectroscopy of adsorbed pyridine and scanning and transmission electron microscopy. It was found that platinum supported only on the zeolite was more active compared to platinum located on the binder. High levels of isoeugenol conversion (ca. 100%), propylcyclohexane yield (56%) and the liquid-phase mass balance (68%) were obtained for the catalyst consisting of Pt supported on both zeolite H-Beta-25 and Bindzil. [ABSTRACT FROM AUTHOR]

Hydrodeoxygenation of isoeugenol was investigated at 200 °C under 3 MPa total pressure in dodecane as a solvent, in hydrogen, over bifunctional Pt‐ and Ir‐modified Beta zeolites and mesoporous materials. As a comparison, Pt and Ir supported on Al2O3, SiO2 and mesoporous MCM‐41 were also tested. The catalysts were characterized by XRD, CO pulse chemisorption, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption and FTIR pyridine adsorption desorption. The results revealed that the most active and selective catalyst was Pt‐H‐Beta‐300, which exhibits the lowest acidity and largest crystal size of Beta zeolite among the studied Pt‐ and Ir‐modified Beta zeolites. Complete conversion of isoeugenol and 89 % selectivity to propylcyclohexane was obtained with this catalyst in 240 min. The overall deoxygenation selectivity was 100 %, giving dialkylated cyclohexanes as the second major product. The catalyst was regenerated, reduced and reused in the hydrodeoxygenation of isoeugenol with almost the same performance as the fresh catalyst. Thermodynamic analyses and kinetic modelling of the data were also performed. [ABSTRACT FROM AUTHOR]

• A clear impact of the precursor on physico-chemical properties of solution impregnated Ni in zeolite 5A and 13X was shown. • Significant differences were also observed in activity and selectivity of the prepared catalysts in CO 2 methanation. • Besides the choice of precursor, the calcination temperature also influenced clearly the performance of the catalysts. • Detailed catalyst characterization was performed. • 13X was concluded to be the superior support and nickel citrate was the best precursor. Zeolite 13X and 5A supported Ni catalysts were synthesized for CO 2 methanation using the evaporation impregnation method. The influence of using different Ni precursors (nitrate, citrate, and acetate) as well as calcination temperatures on the catalyst properties and performance were investigated. XRD, SEM-EDX, TEM, STEM-EDX, N 2 physisorption, H 2- TPR, TPD-NH 3 and TG/DTA were used for detailed characterization of the catalysts. The parent structure of the zeolites did not change during catalyst synthesis. Using nickel citrate and acetate resulted in smaller NiO particle size compared to nitrate. STEM-EDX results showed that all the Ni-precursor complexes entered more efficiently the 13X zeolite structure, which is mainly due to steric hindrance resulting from the smaller pore size of 5A. Methanation experiments revealed that the 13X catalysts synthesized using nickel citrate (5% Ni) displayed clearly higher activity, compared to the catalysts synthesized using nickel nitrate or nickel acetate. A 79% conversion at 320 °C was obtained with 100% selectivity towards CH 4 and the catalyst showed excellent stability during 200 h testing. Overall, it can be concluded that the Ni precursor significantly influences the physico-chemical characteristics and catalytic properties of Ni 13X and Ni 5A zeolite catalysts in CO 2 methanation: complex size and pore size matter. [ABSTRACT FROM AUTHOR]

Sn–Al-Beta zeolite was prepared through a hydrothermal method and further modified by alkali and alkaline earth (e.g. Sr and Ba) metals not practically altering the textural properties of the catalyst. The catalytic materials were tested in glucose transformation to methyl lactate in a batch reactor at 180 °C allowing to correlate catalytic activity and selectivity with the strength and type of acid sites. The results showed that by suppressing the Brønsted acidity of the modified catalyst with different promoters the yield of methyl lactate can be increased from ca. 20% to over 50%. Modification of Sn-Beta zeolite by alkali and alkaline earth (e.g. Sr and Ba) metals not practically altering the textural properties of the catalyst was essential for catalytic properties. The yield of methyl lactate can be increased from ca. 20% to over 50% by suppressing the Brønsted acidity of the modified catalyst with different promoters. [Display omitted] • Modification of Sn-Beta zeolite with alkali and alkaline earth (e.g. Sr and Ba) metals. • Glucose transformations to methyl lactate over these catalysts. • Catalytic activity and selectivity correlated with the strength and type of acid sites. • Suppressing Brønsted acidity increased methyl lactate yield from ca. 30% to over 50%. [ABSTRACT FROM AUTHOR]

Sulfur-free Ni supported on H-Y zeolites, γ-Al 2 O 3 and SiO 2 synthesized by the wet impregnation method, and Pd/C were tested in hydrodeoxygenation (HDO) of stearic acid. The catalysts were forming n- heptadecane except Ni/H-Y-80, which was producing n- heptadecane and n- octadecane. Ni/H-Y 80 and Pd/C were tested on HDO of fatty acid methyl esters from chlorella, tall oil fatty acids, and animal fat. The reactions converting the substrates to the final products followed the path from unsaturated esters to acids, with hydrogenation of the latter into alcohols (i.e., stearyl alcohol), and finally formation of hydrocarbons. Ni/H-Y-80 permitted rapid and complete conversion into hydrocarbons, while Pd/C displayed 5–20 times lower turnover frequency, producing saturated intermediates along with hydrocarbons. The catalyst reusability of Ni supported on Y zeolites was studied by recycling and regenerating the spent catalyst from fatty acid HDO. The catalysts demonstrated the possibility of restoring the rates per unit of surface area after regeneration. Catalysts used in HDO of different feedstocks were investigated by thermogravimetric analysis, inductively coupled plasma-optical emission spectroscopy, transmission electron microscopy, surface area measurements, and pore size analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] •Mono- and bi-metallic Ru and Ni loaded 13X and 5A catalysts were synthesized and characterized. •Ni was able to enter the pores of 13X, in the other case, 5A, an egg shell type structure was formed. •The morphology of the catalyst influenced significantly the selectivity. High conversion of CO 2 and selectivity to CH 4 were obtained, clear differences were observed depending on support and loading. Zeolites 13X and 5A were modified with nickel and/or ruthenium for CO 2 methanation. The catalysts were prepared by evaporation impregnation and XRD, SEM-EDX, TEM, STEM-EDX, nitrogen physisorption, H 2 -TPR and NH 3 -TPD were used to characterize the physico-chemical properties of the catalysts. The physico-chemical characterization results show that the zeolites structure did not change after the Ni, Ru modification, however. Ni was able to enter the pores of 13X, in the other case, 5A, an egg shell type structure was formed. Methanation experiments were performed in a lab scale fixed bed reactor system, the results showed that the mono-metallic catalysts out-performed the bi-metallic ones with Ni being the more active. One of the factors influencing the performance of the bi-metallic catalysts was the difficulty to obtain good dispersion when both metals were used. Also the morphology of the catalyst significantly influenced the selectivity. The catalysts with lower weak acidity benefit for getting a higher activity. The single metal catalysts 2.5 %Ru13X and 5%Ni13X showed good catalytic stability with around 97 % CH 4 selectivity at 360 °C, with no catalyst deactivation during the 200 h catalyst stability test. [ABSTRACT FROM AUTHOR]

Synthesis of Beta zeolite catalysts was carried out using two different methods. The influence of such parameters as synthesis time and temperature, gel composition and gel ripening on the physico-chemical and catalytic properties of Beta zeolite catalysts was studied. A range of analytical methods was applied in this work including scanning and transmission electron microscopies, energy dispersive X-ray spectroscopy, X-ray powder diffraction, nuclear magnetic resonance spectroscopy – 27A1-MAS-NMR and 29Si-MAS-NMR, nitrogen physisorption, Fourier transform infrared spectroscopy and inductively coupled plasma optical emission spectrometry. The sodium forms of Beta zeolites were transformed to the proton forms H-Beta by ion-exchange using aqueous solutions of NH 4 NO 3 and thereafter evaluated in Prins cyclization of (−)-isopulegol with benzaldehyde. The best catalyst synthesized at 150 °C in the rotation mode for 17 h possessing an optimal combination of morphological and structural properties as well as concentration of acid sites demonstrated high (−)-isopulegol conversion (93%) along with high selectivity to the desired product (79%). Image 1 • Influence of the synthesis parameters on properties of Beta zeolites. • Characterization of synthesized Beta zeolites by several methods. • Evaluation of activity in Prins cyclization of (−)-isopulegol with benzaldehyde. • Comparison of synthesized zeolites with a commercial beta zeolite. • High conversion and selectivity to the desired product. [ABSTRACT FROM AUTHOR]