The reaction between CO2 and chloroform in anion-functionalized ionic liquids with the formation of trichloroacetates.

Here, 1,2,4-triazolide-based ionic liquids (ILs), N-ethyl-N,N-dimethyl-N-(2-methoxyethyl)ammonium 1,2,4-triazolide ([MOEN211][Triz]) and tetraethylammonium 1,2,4-triazolide ([N2222][Triz]), are used to capture CO2. The interaction results suggest that CO2 reacts with the anion [Triz]- to form carbamate species. Surprisingly, when deuterated chloroform (CDCl3) or chloroform (CHCl3) is added into the absorption system at room temperature, it is found that CO2 can react with not only the [Triz]- anion but also CDCl3 (or CHCl3) to form carbamate and trichloroacetate species, respectively. In other words, CO2 can easily react with cheap CHCl3 in the presence of [Triz]-based ILs to form valuable chemical trichloroacetate under ambient conditions. Moreover, the formation of trichloroacetate can also be detected in the systems containing imidazolide ([Im]-) and pyrazolide ([Pyr]-) ILs. The findings of this work may provide another useful route for carbon capture and utilization.