A Metal-Organic Framework (MOF), iron-benzenetricarboxylate (Fe(BTC)), has been studied for the adsorptive removal of azo-dye Orange II from aqueous solutions, where the effect of various parameters was tested and isotherm and kinetic models were suggested. The adsorption capacities of Fe(BTC) were much higher than those of an activated carbon. The experimental data can be best described by the Langmuir isotherm model (R2 > 0.997) and revealed the ability of Fe(BTC) to adsorb 435 mg of Orange II per gram of adsorbent at the optimal conditions. The kinetics of Orange II adsorption followed a pseudo-second-order kinetic model, indicating the coexistence of physisorption and chemisorption, with intra-particle diffusion being the rate controlling step. The thermodynamic study revealed that the adsorption of Orange II was feasible, spontaneous and exothermic process (−25.53 kJ·mol−1). The high recovery of the dye showed that Fe(BTC) can be employed as an effective and reusable adsorbent for the removal of Orange II from aqueous solutions and showed the economic interest of this adsorbent material for environmental purposes.

A lignocellulosic residue from the pulp and paper industry (primary sludge) was employed to obtain carbon-based fluorescent nanomaterials. The unprecedented preparation of the carbon quantum dots (CQDs) was carried out using a microwave-assisted reaction catalyzed by a solid acid catalyst, which induced the formation of CQDs. The obtained CDQs were fully characterized using a number of analytical techniques. HR-TEM images depicted particle sizes of average diameter value of 17.5 nm. UV–visible spectra displayed a characteristic peak at 325 nm associated with the formation of CQDs. Fluorescence measurements recorded at 360 nm (excitation wavelength) exhibited an emission band at ca. 435 nm. This emission signal turned out to be dependent on the excitation wavelength that further confirmed the presence of CQDs.

2,5-Dimethylfuran (DMF) has been considered a promising biofuel additive, potentially derived from renewable resources. There have been various reports on DMF production from hydrogenation of 5-hydroxymethylfurfural (HMF). However, most reports employed high hydrogen pressure, long reaction times, and reactions under batch conditions. In this study, Cu−Pd bimetallic catalysts incorporated on reduced graphene oxide (RGO) were used for selective hydrogenation of HMF to DMF using 2-propanol as hydrogen donor under continuous flow conditions. Synthesized catalysts were characterized by N 2 physisorption, SEM-EDX, XRD, XPS, TEM, and H 2 -TPR techniques. 10Cu-1Pd/RGO exhibited 96% HMF conversion with 95% DMF yield under optimum reaction conditions with good stability with time on stream. XRD and XPS results pointed to the presence of a palladium−copper alloy, which could enhance both the activity and especially the stability in the conversion of HMF toward DMF. The effect of temperature, pressure, and feed flow rate were also investigated on the catalytic performance. The stability of catalyst was tested for 8 h time on stream, where it was found that the catalyst displayed good stability.

Selective and efficient production of vanillin from lignin‐derived feedstocks has attracted attention to replace its current manufacturing process. Transition metal‐based catalysts supported on mesoporous aluminosilicate were synthesized using a mechanochemical approach and subsequently investigated in vanillin production via the selective oxidation of isougenol. The mechanochemically synthesized catalysts exhibited a high isoeugenol conversion under mild conditions using H2O2 as oxidizing agent. Nb‐based catalysts were found to provide the optimum conversion/selectivity under the investigated conditions (69% conversion, 66% vanillin selectivity, 2 h reaction). The synergistic effect between Fe/Nb and Al accounts as important key factor for optimum activity of catalytic systems.

Vanillin is one of the most commonly used natural products, which can also be produced from lignin-derived feedstocks. The chemical synthesis of vanillin is well-established in large-scale production from petrochemical-based starting materials. To overcome this problem, lignin-derived monomers (such as eugenol, isoeugenol, ferulic acid etc.) have been effectively used in the past few years. However, selective and efficient production of vanillin from these feedstocks still remains an issue to replace the existing process. In this work, new transition metal-based catalysts were proposed to investigate their efficiency in vanillin production. Reduced graphene oxide supported Fe and Co catalysts showed high conversion of isoeugenol under mild reaction conditions using H2O2 as oxidizing agent. Fe catalysts were more selective as compared to Co catalysts, providing a 63% vanillin selectivity at 61% conversion in 2 h. The mechanochemical process was demonstrated as an effective approach to prepare supported metal catalysts that exhibited high activity for the production of vanillin from isoeugenol.