Finely Tunable Carbon Nanofiber Catalysts for the Efficient Production of HMF in Biphasic MIBK/HO Systems.

This work proposes catalytic systems for fructose dehydration to 5-hydroxymethylfurfural using a series of functionalized carbon nanofibers. The catalysts were synthesized via finely selected covalent grafting in order to include a variety of functionalities like pure Bronsted acid, tandem Brønsted/Lewis acid, and tandem Lewis acid/Lewis base catalysts. After the characterization and evaluation of acidity strength and the amount of acid centers, the catalyst series was screened and related to the product distribution.

New insights for valorization of polyolefins/light alkanes: catalytic dehydrogenation of -alkanes by immobilized pincer-iridium complexes.

This scientific review delves into the innovative realm of polyolefins/light alkanes valorization through their catalytic dehydrogenation employing pincer-ligated iridium organometallic complexes. These widely studied catalysts exhibit outstanding properties, although the intrinsic characteristics of homogeneous catalysis (such as challenging product-catalyst separation, poor applicability to continuous-flow processes and low recyclability) limit their activity and industrial application, as well as their thermal stability. Through the immobilization of complexes on inorganic supports, these downsides have been bypassed, harnessing the true potential of these catalysts, affording more selective and stable catalysts in addition to facilitating their implementation in industrial processes.

Highly Effective Non-Noble MnO Catalysts for 5-Hydroxymethylfurfural Oxidation to 2,5-Furandicarboxylic Acid.

Noble metal-free catalyst or catalytic oxidation of 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid are proposed in this study as a proposal to solve one of the great disadvantages of this reaction of using preferably noble metal-based catalysts. The catalytic activity of six MnO crystal structures is studied as alternative. The obtained results showed a strong connection between catalytic activity the type of MnO structure organization and redox behavior.

Functionalized Biochars as Supports for Ru/C Catalysts: Tunable and Efficient Materials for γ-Valerolactone Production.

Cotton stalks-based biochars were prepared and used to synthetize Ru-supported catalysts for selective production of γ-valerolactone from levulinic acid in aqueous media. Different biochars' pre-treatments (HNO, ZnCl, CO or a combination of them) were carried out to activate the final carbonaceous support. Nitric acid treatment resulted in microporous biochars with high surface area, whereas the chemical activation with ZnCl substantially increases the mesoporous surface.

Highly Active Ce- and Mg-Promoted Ni Catalysts Supported on Cellulose-Derived Carbon for Low-Temperature CO Methanation.

The CO methanation performance of Mg- and/or Ce-promoted Ni catalysts supported on cellulose-derived carbon (CDC) was investigated. The samples, prepared by biomorphic mineralization techniques, exhibit pore distributions correlated to the particle sizes, revealing a direct effect of the metal content in the textural properties of the samples. The catalytic performance, evaluated as CO conversion and CH selectivity, reveals that Ce is a better promoter than Mg, reaching higher conversion values in all of the studied temperature range (150-500 °C).

5-Hydroxymethyl-2-Furfural Oxidation Over Au/CeZrO Catalysts.

A series of gold catalysts supported on pure CeO, ZrO, and two different Ce-Zr mixed oxides have been prepared and tested in the 5-hydroxymethyl-2-furfural oxidation reaction. All catalysts show high catalytic activity (100% conversion) and important selectivity (27-41%) to the desired product i.e.

PFG-NMR as a Tool for Determining Self-Diffusivities of Various Probe Molecules through H-ZSM-5 Zeolites.

The understanding of major zeolite applications is partially based on diffusion of molecules inside or outside microporous networks. However, it is still a challenge to measure such phenomena. The diffusion ordered nuclear magnetic resonance spectroscopy (DOSY) technique has been reported to measure a probe molecule's diffusion inside porous solids.

CO Adsorption Capacities in Zeolites and Layered Double Hydroxide Materials.

The development of technologies that allow us to reduce CO emissions is mandatory in today's society. In this regard, we present herein a comparative study of CO adsorption over three types of materials: zeolites, layered double hydroxides (LDH), and zeolites coated LDH composites. The influence of the zeolite Si/Al ratio on zeolites sorption capacity along with the presence of mesopores was investigated.

Au/CeO-ZnO/AlO as Versatile Catalysts for Oxidation Reactions: Application in Gas/Liquid Environmental Processes.

The present work showcases the versatility of nanogold systems supported on Zn-doped ceria when applied in two important environmental processes, the total CO oxidation, and the liquid phase oxidation of glucose to gluconic acid. In the CO oxidation the suitability of these materials is clearly demonstrated achieving full conversions even at sub-ambient conditions. Regarding the glucose oxidation our materials display high conversion values (always over 50%) and very importantly full or almost full selectivity toward gluconic acid-an added value platform chemical in the context of biomass upgrading routes.