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 celcius 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 byproduct.

Automated summary

Heteroatom enriched cyclophosphazene and triazine based hybrid nanoporous material (CTHM-2) is an efficient metal free catalyst for converting CO2 to valuable products under thermochemical and electrochemical conditions. The catalyst shows high conversion rates and selectivity for cyclic and polycarbonate products, as well as good retention of activity after multiple cycles. It also demonstrates versatility as an electrocatalyst for CO2 conversion to methanol with high Faradic efficiency.