Here, we demonstrate the use of Pt0 nanoparticles immobilised on a polymeric monolithic support as a ligand-free heterogeneous catalytic system for the reduction of 13CO2 at room temperature and atmospheric pressure. The described system effectively reduces 13CO2 with dihydrosilanes as the hydrogen source to yield a mixture of silylformates, silylacetals and methoxysilanes, which upon further hydrolysis with D2O, produces their respective C1-type products, that is H13COOD, 13CH2(OD)2 and 13CH3OD. If a monohydrosilane was used as the hydrogen source, a selective reduction of 13CO2 to a product mixture of only silylformates was observed. Addition of diethylamine to this reaction mixture results in the formation of H13COOH and Et2N13CHO. This robust catalytic system is not only maintenance-free and simple to handle, as compared with organometallic and organocatalyst systems, but also shows 3- to 11-fold better catalytic activity and exhibits higher turnover numbers (TONs) up to 21 900 (activity=6.22 kg gPt−1 bar−1).