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This study presents results on aldol condensation of furfural and cyclohexanone in presence of Mg‐Al hydrotalcite‐derived materials as solid basic catalysts at reaction temperatures from 25 to 90 °C and a cyclohexanone to furfural molar ratio of 1–10. Mg‐Al mixed oxide exhibited reasonable activity with furfural conversion of ca. 50 % after 180 min of the reaction at T=90 °C. The activity of reconstructed hydrotalcite was much higher with furfural conversion close to 100 % at short reaction times. In comparison with Mg‐Al mixed oxide, the initial reaction rate has increased 30–50 times. Under similar reaction conditions, cyclohexanone self‐condensation on HTC‐derived catalysts could not compete with aldol condensation because the former reaction was inhibited by produced water. The change in CH/F molar ratio influenced both furfural conversion and product selectivity; higher furfural content in the reaction mixture favored the second condensation step.

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MgGa layered double hydroxides (Mg/Ga = 2–4) were synthesized and used for the preparation of MgGa mixed oxides and reconstructed hydrotalcites. The properties of the prepared materials were examined by physico-chemical methods (XRD, TGA, NH3-TPD, CO2-TPD, SEM, and DRIFT) and tested in aldol condensation of furfural and acetone. The as-prepared phase-pure MgGa samples possessed hydrotalcite structure, and their calcination resulted in mixed oxides with MgO structure with a small admixture phase characterized by a reflection at 2θ ≈ 36.0°. The interaction of MgGa mixed oxides with pure water resulted in reconstruction of the HTC structure already after 15 s of the rehydration with maximum crystallinity achieved after 60 s. TGA-MS experiments proved a substantial decrease in carbonates in all rehydrated samples compared with their as-prepared counterparts. This allowed suggesting presence of interlayer hydroxyls in the samples. Acido-basic properties of MgGa mixed oxides determined by TPD technique did not correlate with Mg/Ga ratio which was explained by the specific distribution of Ga atoms on the external surface of the samples. CO2-TPD method was also used to evaluate the basic properties of the reconstructed MgGa samples. In these experiments, an intensive peak at T = 450°C on CO2-TPD curve was attributed to the decomposition of carbonates newly formed by CO2 interaction with interlayer carbonates rather than to CO2 desorption from basic sites. Accordingly, CO2-TPD method quantitatively characterized the interlayer hydroxyls only indirectly. Furfural conversion on reconstructed MgGa materials was much larger compared with MgGa mixed oxides confirming that Brønsted basic sites in MgGa catalysts, like MgAl catalysts, were active in the reaction. Mg/Ga ratio in mixed oxides influenced product selectivity which was explained by the difference in textural properties of the samples. In contrast, Mg/Ga ratio in reconstructed catalysts had practically no effect on the composition of reaction products suggesting that the basic sites in these catalysts acted similarly in aldol condensation of acetone with furfural. It was concluded that the properties of MgGa samples resembled in a great extent those of MgAl hydrotalcite-based materials and demonstrated their potential as catalysts for base-catalyzed reactions.

Acid-modified phonolite material, Al 2 O 3 /foam zeolite and foam zeolite were used as supports for NiW catalysts. The zeolite type materials were prepared by a novel procedure from natural clinoptilolite. Phonolite materials were loaded with 5, 7.5 and 10 wt% of Ni containing 10, 7.5 and 5 wt% of W. Al 2 O 3 /foam zeolite contained 4 and 13 wt% of Ni and W and pure foamed zeolite was effectively loaded with 5 and 16 wt% of Ni and W. NiW/Al 2 O 3 catalyst (3 wt% Ni and 11 wt% of W) was used for comparison of catalytic properties of synthesized materials. Catalytic tests were carried out in an autoclave pressurized at 7 MPa (H 2 ) at room temperature and then heated to 365 °C for 1 h. Catalysts were characterized by N 2 physisorption, XRD, XRF, NH 3 -TPD, CO 2 -TPD and H 2 -TPR. Catalyst properties were compared for the HDO of rendering fat into hydrocarbons. The liquid products were analyzed by simulated distillation, C, H, N, S elemental analysis, ATR and density (15 °C). Gaseous products were characterized by RGA-GC. Used catalysts were also analyzed by N 2 -TGA and O 2 -TGA. Novel phonolite modified solids and NiW/foam zeolite type materials were tested for the first time as catalysts being in some cases more active than NiW/Al 2 O 3 material. Ni(5%)W(10%)/Acid phonolite and NiW/Foamed Zeolite resulted to be the most active materials for the HDO and hydrocracking reactions. The lowest amount of carbonaceous species on the surface of tested catalyst was found for the Ni(5%)W(10%)/Acid phonolite solid.