ABSTRACT This thesis has been focused on the design and preparation of mono- and multi-functional catalysts based on metal nanoparticles (MNPs) using different synthetic strategies. These MNPs have been stabilized on surfaces of basic porous materials and alternative reaction media of ionic nature (ionic liquids), in both cases operating as efficient catalysts for reactions of interest. A first series of MNPs has been stabilized in imidazolium cation derived ionic liquids (ILs), which have also provided an alternative reaction medium to conventional solvents. The cyclopropanation of alkenes using ethyl diazoacetate (EDA) as carbene ion source has been carried out and the influence of metal nanoparticle size and the counterion on the catalyst activity and selectivity has been studied in this reaction medium. A second series of MNPs has been stabilized on basic solid surfaces using impregnation, coprecipitation, deposition and sol-gel methods, hence yielding a high metal dispersion as well as an optimal size in the nanoscale range. These materials have been applied as catalysts in intensification of chemical processes involving sequential transformations or cascade reactions based on hydrogen transfer methodology for the formation of C-N and C-C bonds: a) monoalkylation of amines with alcohols and b) monoalkylation of methylene compounds (benzonitrile, nitromethane and diethyl malonate) with alcohols. In both cases, kinetic studies as well as in situ spectroscopic characterization techniques have been used to determine the reaction mechanism. In a last chapter, in order to get essential information on the mode of action of the MNP-based catalyst, a more detailed study has been carried out from two complementary perspectives: (1) using theoretical calculations based on the Density Functional Theory (DFT), applied to different models of metal atoms with different degrees of coordination, and (2) comparing with experimental kinetic results. This study intends to get key essential information in order to understand the mode of action of catalysts using techniques and high-performance devices.