What are the differences between 1) Metal Organic Frameworks (MOFs), 2) Covalent Organic Polymers (COFs) and 3) Porous Organic Polymers (POPs)?? 2 are the same like 1, but there is no coordination bond just covalent bonds? 3 there is no metal atom? how to distinguish between such a similar species?

 

I think you are right about the differences between all 3 species. MOFs and COFs are both porous and crystalline. POPs are porous, amorphic and noncrystalline. However their pores are nonuniform which makes them the hardest of the 3 to use as catalysts since the nature of their pores is unpredictable.

 

MOFs consists of coordination bonds between the transition metal cations and the organic linkers. COFs are made of light elements that form covalent bonds. With POPs I'd say covalent bonds play a role as well.