Ceria-based nanostructures, employed as catalytic supports for noble and non-noble metals, are well-known for their remarkable activity in steam-reforming reactions, exceptional resistance to degradation, and thermal stability. However, the catalytic activity and selectivity of such systems are strongly dependent on the size and shape of ceria, making it possible to tune the oxide properties, affecting catalyst design and performance. The rational manipulation of ceria nanostructures offers various features that directly impact steam-reforming transformations, including the possibility of tuning oxygen vacancies, redox properties, and oxygen storage capacity. Thus, the importance of shape control in ceria nanomaterials is highlighted herein, emphasizing how the surface atomic configurations (exposure of different facets) significantly impact their efficiency. Although the main focus of this review is to discuss how the catalyst design may affect the performance of hydrogen production, some other elemental studies are shown, when necessary, to exemplify the level of deepness (or not) that literature has reached. Thus, an overview of ceria properties and how the physicochemical control of nanostructures contributes to their tuning will be presented, as well as a discussion regarding elemental materials design and the most prominent synthetic procedures; then, we select some metals (Ni, Co, and Pt) to discuss the understanding of such aspects for the field. Finally, challenges and perspectives for nanoengineering catalysts based on shape-controlled ceria nanostructures will be described to possibly improve the performance of designed catalysts for steam-reforming reactions. Although there are other literature reviews on ceria-based catalysts for these reactions, they do not specifically focus on the influence of the size and shape of the oxide.

This study presents a series of Interzeolite Transformation Intermediates (ITIs) derived from FAU-to-FER interconversion. These hybrid materials, obtained through precise control of the interconversion process, exhibit both large mesoporosity and FER topology-type pore confinement, resulting in high conversion and remarkable shape selectivity despite their disordered structure at the long range. We demonstrated this unique combination of properties in three different catalytic tests. The local order within these ITIs is sufficient to create pore confinement, which not only produces remarkable shape selectivity but also enhances conversion by increasing accessibility. Specifically, the ITIs show a 10-fold increase in activity for Friedel-Crafts alkylation, a 16-fold increase in activity for triisopropylbenzene (TiPBz) cracking, and a two-fold increase in methanol dehydration to dimethyl ether (DME) compared to commercial ferrierite all while maintaining the selectivity of FER. These results highlight the potential of FAU-to-FER ITIs as high-performance catalysts that combine the accessibility of disordered structures with the selectivity typically associated with well-ordered zeolites, opening avenues in zeolite-based catalysis.

Yeast recycling, which is a common practice in sugarcane ethanol plants, could be expanded if it could be successfully implemented in corn-based ethanol production. However, the process of recycling the yeast remaining after fermentation is hampered by contaminating microorganisms that reduce the fermentation efficiency and compete with the yeast for the fermentable sugars. Currently, antibiotics are used to control microbial contamination. This study proposes chlorine dioxide and electron beam irradiation as alternative control methods for completely inactivating contaminants and minimizing their effect on recycled yeast. For that, wort sterilization using electron radiation (20 kGy) and treatment with a chemical biocide, namely chlorine dioxide (125 mg kg⁻¹), were compared with non-treated wort. Five fermentation cycles were performed using fed-batch systems with 300 g L⁻¹ of fermentable sugars. The results obtained in this study showed the inactivation of contaminants under the effect of electron beam irradiation, which led to an increase in the productivity, yield, and efficiency of fermentation by 0.21 g L⁻¹h⁻¹, 2.6%, and 4.7%, respectively. However, ClO₂ did not show promising results in reducing contamination or improving fermentative parameters. Thus, electron beam irradiation of contaminated wort may be a suitable alternative to chemical biocides and would allow the use of recycled yeast in corn-based ethanol plants.

The development of catalysts capable of overcoming mass transport limitations remains a crucial challenge in hydrocracking processes, particularly for bulky linear hydrocarbons, such as long-chain paraffins. In this study, we report the synthesis of hierarchical Pt/HUSY catalysts via a surfactant-templating strategy that introduces highly interconnected intracrystalline mesoporosity while preserving most of the zeolite’s crystallinity and acidity, significantly enhancing molecular diffusion, facilitating better access to acid sites, and alleviating the diffusion limitations typically associated with purely microporous zeolites. Catalytic testing revealed a marked increase in hexadecane cracking activity, especially in catalysts with longer surfactant treatment times (Pt/CBV780_20h and Pt/CBV720_41h), which exhibited superior conversion rates and selectivities toward lighter hydrocarbons. Notably, the surfactant-templated catalysts achieved similar product distributions at lower temperatures than those of their parent materials. Additionally, our study demonstrates the importance of well-connected intracrystalline mesoporosity in reducing catalyst deactivation by preventing coke accumulation, particularly in high-aluminum Pt/CBV720 catalysts, which showed higher stability over time despite greater coke deposition. These findings highlight the effectiveness of surfactant-templated mesoporosity as a powerful strategy to enhance both the performance and lifetime of zeolite-based catalysts for industrial hydrocarbon conversion processes.