DESIGN of MONO and BIMETALLIC NANOMATERIALS for BIOMASS VALORIZATION THROUGH TANDEM REACTIONS

Abstract

This work involved the development and characterization of metal-based heterogeneous catalysts for tandem reactions, comprising the selective oxidation of biomass-derived aromatic alcohols towards the respective aldehydes, and the subsequent reductive amination into amines. This research project focused on the design of nanomaterials, modulating their catalytic performance by modifying the metal-loading and/or by the formation of bimetallic counterparts. Moreover, the project was directed at tuning the reaction conditions to achieve maximum yields of secondary and tertiary amines, whose applications could range from agrochemicals, pharmacophores, cosmetics, pesticides, and building blocks. The synthesis of supported metal nanoparticles was conducted employing fishery waste-derived chitin, which applications are often hindered by its low solubility in most media, thus, finding alternative uses could have a positive impact on its waste-management. As part of this research project, recyclability tests were performed. Furthermore, the synthesis of the catalytic samples was also investigated using a twin-screw extruder, through a solvent-free continuous-flow mechanochemical protocol. The resulting catalytic materials were characterized by employing a multi-technique approach, including XPS, XRD, SEM, TEM, ICP-MS, and N -physisorption. Catalytic tests for the tandem reactions were performed under batch conditions in pressurized reactors (autoclaves). In terms of conversion and selectivity, the reaction outcome has been checked by H NMR and GC-FID to verify reproducibility. On the other hand, GC-MS and NMR spectroscopy (H NMR, C NMR, and bidimensional NMR) were employed for the products' identification.