The catalytic activity for the production of biodiesel with three morphologically different nanocrystalline MgO materials prepared using simple, green and reproducible methods was investigated. The nanocrystalline samples studied were MgO(111) nanosheets (MgO (I)), conventionally prepared MgO (MgO (II)) and aerogel prepared MgO (MgO (III)). The methods to produce the catalysts included: (a) 4-methoxy-benzyl alcohol templated sol-gel process followed by supercritical drying and calcination in air at 773 K (MgO (I)), (b) from a commercial MgO that was boiled in water, followed by drying at 393 K, and dehydration under vacuum at 773 K (MgO (II)), and (c) viahydrolysis of Mg(OCH₃)₂ in a methanol–toluene mixture, followed by supercritical solvent removal with the formation of a Mg(OH)₂ aerogel that was dehydrated under vacuum at 773 K (MgO (III)). These catalysts were characterized by TEM, DRIFT, and DR-UV-Vis and tested in the transesterification of sunflower and rapeseed vegetable oils at low temperatures, under different experimental conditions: autoclave, microwave and ultrasound. Working with these materials under microwave conditions provided higher conversions and selectivities to methylesters compared to autoclave or ultrasound conditions. Under ultrasound, a leaching of the magnesium has been evidenced as a direct consequence of a saponification reaction. These systems also allow working with much lower ratios of methanol to vegetable oil than reported in the literature for other heterogeneous systems. The activation temperature providing the most active catalysts was found to vary depending on the exposed facet: for MgO(111) structures (i.e.MgO (I)) this was 773 K, while for MgO (110) and (100) (i.e.MgO (II) and MgO (III)) this was 583 K.

A new approach of inserting rhenium into a TiO ₂ structure generates Brønsted acid sites which are essential for conversion of carbohydrates into levulinic acid.

Analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) such as paracetamol, diclofenac, and ibuprofen are frequently encountered in surface and ground water, thereby posing a significant risk to aquatic ecosystems. Our study reports the catalytic performances of nanosystems TiO₂-Me_xO_y (Me = Ce, Sn) prepared by the sol-gel method and deposited onto glass slides by a dip-coating approach in the removal of paracetamol from aqueous solutions by catalytic ozonation. The effect of catalyst type and operation parameters on oxidation efficiency was assessed. In addition to improving this process, the present work simplifies it by avoiding the difficult step of catalyst separation. It was found that the thin films were capable of removing all pollutants from target compounds to the oxidation products.

Catalytic biomass valorization into value-added chemicals is crucial to reduce reliance on fossil resources and mitigate environmental impacts. However, more than 90% of chemical manufacturing still relies on conventional catalysts, underscoring the need for sustainable alternatives. Three-dimensional (3D) printing offers unique opportunities to design catalysts with tailored geometries and pore architectures, enhancing mass transfer, active site accessibility, and reusability. Most reviews of 3D-printed catalysts focus on small molecule reactions such as ammonia decomposition or methanol dehydration. In contrast, this review was conceived to provide a comprehensive overview on the design and application of 3D-printed catalysts in biomass conversion. Recent advances in metal-based, acid/base-mediated, enzymatic and photocatalytic systems are discussed, while assessing the benefits and drawbacks of 3D printing compared to traditional catalyst fabrication. By addressing current challenges and outlining future directions, this review highlights the capacity of 3D-printed catalysts to bridge laboratory innovation and industrial application, paving the way for scalable, cost-effective, and sustainable green chemical manufacturing in the emerging circular bioeconomy.