Selective Reduction of CO_2 with Silanes over Platinum Nanoparticles Immobilised on a Polymeric Monolithic Support under Ambient Conditions

摘要

Here, we demonstrate the use of Pt~0 nanoparticles immobilised on a polymeric monolithic support as a ligand-free heterogeneous catalytic system for the reduction of ~(13)CO_2 at room temperature and atmospheric pressure. The described system effectively reduces ~(13)CO_2 with dihydrosilanes as the hydrogen source to yield a mixture of silylformates, silylacetals and methoxysilanes, which upon further hydrolysis with D_2O, produces their respective C1-type products, that is H~(13)COOD, ~(13)CH_2(OD)_2 and ~(13)CH_3OD. If a monohydrosilane was used as the hydrogen source, a selective reduction of ~(13)CO_2 to a product mixture of only silylformates was observed. Addition of diethylamine to this reaction mixture results in the formation of H~(13)COOH and Et_2N~(13)CHO. 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 21900 (activity=6.22 kg_(CO_2)g_(Pt)~(-1) bar~(-1)).