Thermochemical and electrochemical CO2 reduction by a cyclophosphazene and triazine based inorganic–organic hybrid nanoporous metal-free catalyst

Heteroatom enriched (S = 46 wt%, N = 21 wt%) cyclophosphazene and triazine based hybrid nanoporous material (CTHM-2) is reported as an efficient metal free catalyst for the conversion of CO2 to valuable products via thermochemical and electrochemical approaches. The ultrafast microwave assisted synthesis is used to synthesize CTHM-2 via poly-condensation reaction. The heterogeneous CTHM-2 catalyst without any co-catalyst shows 100 % CO2 conversion into cyclic and polycarbonate thermochemically under the experimental condition of 100 ℃ and 4 bar pressure. Also, the catalyst shows 79 % retention of its initial activity with high selectivity of cyclic carbonate (88 %) even after 5 cycles. Moreover, the versatility of the catalyst was proven when the same specimen has been used as electrocatalyst for the conversion of CO2 into methanol. The catalyst shows Faradic efficiency of 66.68 % at a potential of −­0.6 V vs RHE for methanol formation with hydrogen gas as the by-product.