Designing efficient and facile recoverable catalysts is desired for sustainable biomass valorization. This work reports the one-pot synthesis of a novel magnetic Fe­(NiFe)­O4–SiO2 nanocatalyst for hydrogenation of biomass-derived furfural into valuable furfuryl alcohol. Various techniques were used to systematically analyze the physicochemical properties of the Fe­(NiFe)­O4–SiO2 nanocatalyst. Vibrating sample magnetometer analysis reveals low coercivity of Fe­(NiFe)­O4–SiO2 (6.991 G) compared with that of Fe3O4–SiO2 (27.323 G), which is attributed to highly dispersed Ni species in the Fe­(NiFe)­O4–SiO2 catalyst. HRTEM images indicated the nanosized nature of the Fe­(NiFe)­O4–SiO2 catalyst with an average diameter of ∼14.32 nm. The Fe­(NiFe)­O4–SiO2 catalyst showed a superior BET surface area (259 m2/g), which is due to the formation of nanosized particles. The magnetic Fe­(NiFe)­O4–SiO2 nanocatalyst shows a remarkable performance with 94.3 and 93.5% conversions of furfural and ∼100% selectivity of furfuryl alcohol at 90 °C and 20 H2 bar and 250 °C and 5 H2 bar, respectively. Using heptane as a solvent, the effect of temperature, pressure, reactant amount, and catalyst loading were investigated to optimize the reaction conditions. A probable mechanism via a non-hydrogen spillover route was proposed for the hydrogenation of furfural to furfuryl alcohol over the magnetic Fe­(NiFe)­O4–SiO2 nanocatalyst. The efficiency of the magnetic Fe­(NiFe)­O4–SiO2 nanocatalyst is attributed to highly dispersed nickel species, which plays a key role in the dissociation of H2 into a proton and a hydride in the furfural hydrogenation. The superior performance of the magnetic Fe­(NiFe)­O4–SiO2 nanocatalyst, along with the advantages of low cost and easy recoverability, could make it a new appealing catalyst in various selective hydrogenation reactions.

Hierarchical ZnO/ZSM-5 catalysts were prepared by desilication and impregnation with 2 wt % metallic ZnO. X-ray diffraction and Fourier transform infrared (FTIR) results showed that the structures of the hierarchical zeolites were relatively preserved despite desilication but were accompanied with sequential loss in crystallinity, likewise Bro̷ nsted acidity causing decline in conversion or activity of the catalyst. However, pyridine FTIR shows enhancement of the Bro̷ nsted acidic sites. Throughout the activity test, the hierarchical ZnO/ZSM-5 catalysts showed an outstanding performance within 5 h on stream with the average aromatic (benzene, toluene, and xylenes) selectivity trend, represented by their NaOH concentrations 0.3 M > 0.4 M > 0.2 M > 0.1 M corresponding to 61.0, 53.5, 40.3, and 36.8%, respectively. Their average propane conversions within the same period followed a consecutive trend 0.1 M > 0.2 M > 0.3 M > 0.4 M conforming to 34.1, 24.8, 17.3, and 10.2%, respectively. These were compared with that of the reference (ZnO/ZSM-5), which exhibited an average aromatic selectivity of 25.2% and propane conversion of 39.7%. Furthermore, the hierarchical catalyst generally displayed a low amount of C9+ heavier aromatics with the ZnO/ZSM-5(0.3 M) catalyst having the lowest C9+ selectivity of 23.7% compared to the reference catalyst with 72.7% at the same time on stream.

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First time application of Al-SBA-15 supported Ni catalysts for hydrodeoxygenation of dibenzofuran to hydrocarbons was investigated in this study.

Light alkane aromatization for aromatic compound production, used in petrochemical industries is an attractive area of research. The effect of second metal co-impregnation was investigated in stabilizing zinc on ZSM-5 in aromatization of propane. HZSM-5 was modified with zinc and iron metal by co wet-impregnation and characterized using XRF, XRD, BET, N2-adsorption, FTIR, FTIR-Pyridine, SEM, TEM, H2-TPR and XPS. The effect of different loadings of Iron on Zn/ZSM-5 was investigated on acidity, aromatic yield, product distribution and aromatization performance. Performance test was conducted in a fixed bed reactor at 540 °C, one atmosphere. GHSV of 1200 mL/g-h. Co-impregnation of Zn with Fe improved the catalytic activity and aromatic yield for 10 h time on stream as compared to parent HZSM-5 and Zn/ZSM-5 of very low aromatic yield and propane conversion. Impregnation of Zn as the dehydrogenating metal on HZSM-5 steadily increased aromatic yield from 5% on HZSM-5 to 25% and was steadily dropped to 20% after 10 h TOS. The co-impregnation of iron of 1–3 wt% loading as the second metal for zinc stability with 2 wt% Zn on ZSM-5 improved propane conversion and aromatic yield to 55% for the 10 h TOS. This further enhanced aromatic product distribution and minimized light gases.

A magnetically recyclable eggshell-based catalyst (MKEC) was synthesized to circumvent saponification during the conversion of neem, Jatropha, and waste cooking oils (free fatty acid, 2.3e6.6%) to biodiesel. The characterization results indicated that MKEC had a mesoporous structure with the pore width of 3.24 nm, a specific surface area of 128 m 2 /g, and a pore volume of 0.045 cm 3 /g. The results confirmed that the MKEC is more tolerant to fatty acid poisoning than calcined eggshell. The effects of process parameters for maximum fatty acid methyl ester (FAME) content were evaluated by central composite design (CCD) and artificial neural network (ANN). The experimental FAME content of 94.5% was achieved for neem oil with a standard deviation (SD) of 0.68, which was in reasonable agreement with predicted values (CCD, 96.9%; ANN, 95.9%; SD, 0.73). The reusability studies showed that the mesoporous catalyst can be reused efficiently for five cycles without much deterioration in its activity.

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This work shows how propane was catalytically converted to aromatic compounds over Zn-Ni/HZSM-5 to investigate the synergistic role of nickel as zinc stabilizer and promoter in propane aromatization. Coimpregnation method was employed for Zn-Ni/ZSM-5 synthesis xed 2 wt. % of zinc and 1, 2 and 3 wt. % of nickel. Modi ed catalysts were fully characterized. Catalysts crystallinity, structure and microporosity were retained from analysis results. Propane aromatization process was conducted at 540 o C, 1200 ml/gh gas hourly space velocity and atmospheric pressure. The presence of Ni with Zn improved catalytic performance for all Ni loading. Aromatic selectivity and propane conversion were improved with best performance to be Zn-Ni/ZSM-5 with 2 wt. % Zn, 2 wt. % Ni on ZSM-5 averaging 88 and 60 % for twelve hours' time on stream. Aromatic selectivity on Zn-Ni/ZSM-5 is eight times better than the parent HZSM-5 and one and half times better than the Zn/ZSM-5 catalyst. The electronic interaction of zinc and nickel resulting from equality of oxidation state of +1 and +2 and metal binding energy change synergistically improved the catalytic performance of the bimetallic Zn-Ni/ZSM-5 over the HZSM-5 and Zn/ZSM-5.Flowrate increase from 6 to 35 ml min -1 was found to decrease propane conversion from 80-40 % with increased aromatic selectivity from 55-80 %. Temperature increase from 500-580 o C favours both propane conversion and aromatic selectivity increase from 50-68 and 55-92 % respectively. The metallic interactions from H 2 -TPR and XPS analysis revealed strong improvement on propane conversion, aromatic selectivity and product distribution.