Simultaneous CO capture and metal purification from waste streams using triple-level dynamic combinatorial chemistry.

A reduction in CO emissions is required to mitigate global warming. Post-combustion carbon capture is one of the most developed technologies that has the potential to meet this goal, but its cost prevents its widespread use. A different approach would be to use CO directly as it is captured, before it is stored. Here we explore spontaneous CO fixation by industrial polyamines as a strategy to generate dynamic libraries of ligands for metal separation and recovery. We identify the CO loadings and solvents promoting the optimal precipitation of each metal from the dynamic libraries of complexes. We demonstrate the separation of lanthanum and nickel using the exhaust gas of an internal combustion engine vehicle, and show that the three metal constituents of the LaNiCo alloys used to manufacture the batteries of electric vehicles can be separated and recovered by successive CO-induced selective precipitations. Beyond the concept of CO-sourced multi-level dynamic coordination chemistry, this study provides a potential framework for integrated CO capture and use through sustainable processes.