The covalently heterogenisation of a free-base porphyrin on SBA-15 silica yielded TPPH2@SBA-15 (TPPH2 = tetraphenyl porphyrin), which was very efficient to promote the CO2 cycloaddition to three-membered rings. The TPPH2@SBA-15/TBAX-based catalytic procedure was very general, as revealed by excellent activities registered in the reaction of CO2 with epoxides, N-alkyl and N-aryl aziridines, forming cyclic carbonates, N-alkyl and N-aryl oxazolidinones, respectively. It is worth noting that this is the first example of the heterogeneously catalysed synthesis of N-aryl oxazolidinones from corresponding N-aryl aziridines. The scale-up of the methodology highlighted that catalytic performances of all the three investigated reactions were maintained also working at a gram-scale to pave the way for future developments of the procedure. In addition, the recycle of TPPH2@SBA–15 for several consecutive reactions was efficient and observed catalytic activities were very similar to those registered in the presence of a fresh material. All the acquired data indicated an excellent sustainability of the catalytic protocol to envisage upcoming practical applications.