In summary, we demonstrated the crucial roles of the chosen Friedel-Crafts catalyst, the crosslinker unit and the degree of crosslinking in the formation of porous polyphosphines, functioning as active macroligands for the CO2 activation. Under FeCl3-catalyzed crosslinking conditions, the PPh3 building blocks do not form an insoluble skeleton without the addition of framework-providing co-monomers and require the activation through stronger Lewis acids.