In the last decade, heterogeneous catalysts have attracted much interest because of their general advantages  that have been boosted thanks to the use of nanomaterials [2–4]. In fact, nanoparticles (NPs) are increasingly used in catalysis since their enhanced reactivity significantly reduces the quantity of catalytic material required to carry out reactions with a high turnover [1, 2, 5]. However, following the basic principles of nanosafety, the prevention of uncontrollable escape of these materials to the reaction media as well as the minimization of the probability of their appearance in the environment is becoming a crucial issue [3–6]. In this sense, the synthesis of polymer-metal nanocomposites (PMNCs) [1, 7–10], obtained by the incorporation of metal nanoparticles (MNPs) in polymeric matrices, has demonstrated to be an attractive approach [5, 8]. By stabilizing MNPs in a polymeric matrix, it is possible to prevent their escape to the reaction medium, thus providing an easy separation of the catalyst from the reaction mixture which, in turn, allows the possibility to reuse the catalytic species without losing efficiency.
One of the methodologies that allow obtaining these PMNCs in a feasible way is the so-called intermatrix synthesis (IMS) [8, 11, 12], based on the dual function of the matrix, which stabilizes the MNPs preventing their uncontrollable growth and aggregation and provides a medium for the synthesis. IMS proceeds by a simple two sequential steps: (a) the immobilization of metal cations (MNPs precursors) inside the matrix and (b) the reduction of metal ions to the zero-valent state leading to the formation of MNPs.
The main goal of this work is the development of advanced nanocomposite materials obtained by the incorporation of silver nanoparticles (AgNPs) in typical textile fibers (polyacrylonitrile, PAN, and polyamide, PA) and in polyurethane foams (PUFs). Yet, up to now, the IMS technique has been applied to polymers bearing ionogenic functional groups that retain the MNPs ion precursors [8, 13, 14]. Regarding this issue, and taking into account the nature of some of the polymeric matrices (e.g., PUF), it was considered essential to activate the support material to obtain an acceptable value of ion exchange capacity (IEC).
Finally, in order to evaluate the catalytic activity of the different developed PMNCs, a model catalytic reaction was carried out in batch experiments: the reduction of p-nitrophenol (4-np) to p-aminophenol (4-ap) in the presence of NaBH4 and metallic catalyst .