Catalytic Processes for The Valorisation of Biomass Derived Molecules

In the last decades, inedible lignocellulosic biomasses have attracted significant attention for being abundant resources that are not in competition with agricultural land or food production and, therefore, can be used as starting renewable material for the production of a wide variety of platform chemicals. The three main components of lignocellulosic biomasses are cellulose, hemicellulose and lignin, complex biopolymers that can be converted into a pool of platform molecules including sugars, polyols, alchols, ketons, ethers, acids and aromatics. Various technologies have been explored for their one-pot conversion into chemicals, fuels and materials. However, in order to develop new catalytic processes for the selective production of desired products, a complete understanding of the molecular aspects of the basic chemistry and reactivity of biomass derived molecules is still crucial. This Special Issue reports on recent progress and advances in the catalytic valorization of cellulose, hemicellulose and lignin model molecules promoted by novel heterogeneous systems for the production of energy, fuels and chemicals

Gold supported on iron oxy-hydroxides: a versatile tool for the synthesis of fine chemicals

A comprehensive overview on gold supported on iron oxy-hydroxides as tool for the synthesis of fine chemicals is given. We will discuss on the catalytic activity of gold supported on iron oxy-hydroxides in several reactions of potential industrial interest, comprising the selective oxidation of primary alcohol to aldehyde, the selective reduction of α,s unsaturated aldehydes and ketones to the corresponding a,b unsaturated alcohols. Furthermore, a significant application of gold supported on iron oxy-hydroxides is the direct synthesis of hydrogen peroxide from H2 and O2. The versatility showed by Au supported on oxy-hydroxides catalysts is an aspect of great importance for industrial applications

Synthetic strategies for the enhancement of Mg(OH)2 thermochemical performances as heat storage material

Abstract This work deals with the study of influence of multi walled carbon nanotubes (CNTs) characteristics on thermochemical performance of hybrid materials based on Mg(OH) 2 (M) as heat storage medium. Two different functionalized CNTs samples are investigated, separated curly tubes (SN) and bundles of straight nanotubes (BN). Hybrids were synthesized by reverse deposition precipitation method and their structure was characterized by X-ray analysis and scanning electron microscopy. The heat storage performance was studied through a thermogravimetric apparatus, simulating heat storage/release cycles. It is demonstrated that separated CNTs owning mainly carboxylic groups increase the interaction with precipitated magnesium hydroxide, improving the reacted fraction during dehydration/hydration cycle. In terms of dehydration/hydration conversion the samples' rank is SN-M>Mg(OH) 2 >BN-M. SN-M exhibits higher heat storage/output capacity (~1250 kJ/kg Mg(OH)2 , ~350 MJ/m 3 )

Influence of the Cobalt Phase on the Highly Efficient Growth of MWNTs

In this work, the influence of the cobalt phase on the growth of carbon nanotubes by the catalytic chemical vapour deposition of CH4 with catalysts containing Co, Mo and Mg is investigated. To this end, the catalytic behaviour of physically mixed CoO/MgO+MgMoO4 and CoMoO4+MgMoO4 is studied. The results obtained show that CoMoO4+MgMoO4 allows for the attainment of the highest CNT yield (2407 wt % against 1296 wt %). Its higher activity is ascribed to the greater formation of active sites that, in light of current assessments, are constituted by metallic cobalt adjacent to Mo2C, and the huge exfoliation of the catalyst, which contributes towards enhancing their exposure

Tethering of Gly-Arg-Gly-Asp-Ser-Pro-Lys Peptides on Mg-Doped Hydroxyapatite

Stem cell homing, namely the recruitment of mesenchymal stem cells (MSCs) to injured tissues, is highly effective for bone regeneration in vivo. In order to explore whether the incorporation of mimetic peptide sequences on magnesium-doped (Mg-doped) hydroxyapatite (HA) may regulate the homing of MSCs, and thus induce cell migration to a specific site, we covalently functionalized MgHA disks with two chemotactic/haptotactic factors: either the fibronectin fragment III1-C human (FF III1-C), or the peptide sequence Gly-Arg-Gly-Asp-Ser-Pro-Lys, a fibronectin analog that is able to bind to integrin transmembrane receptors. Preliminary biological evaluation of MSC viability, analyzed by 3-(4,5-dimethyl­thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, suggested that stem cells migrate to the MgHA disks in response to the grafted haptotaxis stimuli