This describes homogeneous catalysts that are recoverable from solution by being phase selective and through host-guest interactions. An example of a method includes separating a water soluble N-heterocyclic carbene homogeneous catalyst from a solution by: (a) forming a host-guest compound between the catalyst and an inclusion compound in the solution; and (b) isolating the host-guest compound from the solution.

This disclosure concerns a method of forming a covalent organic framework (COF) membrane, comprising forming a membrane substrate by impregnating a porous polymer with a pore-forming agent in order to form an impregnated polymer, at least partially carbonising the impregnated polymer at a temperature of about 150 C. to about 500 C. in order to form the membrane substrate, and interfacially polymerising amino monomers and acyl monomers on a surface of the membrane substrate in order to form the COF membrane. The membrane substrate is characterised by a crystallinity of about 10% to about 70% relative to the porous polymer. The disclosure also concerns the COF membrane thereof, and the use of the COF membrane in catalyst recovery.

A method of carbon dioxide fixation includes contacting a covalent organic framework material with a co-catalyst and an epoxide in the presence of carbon dioxide to form a cyclic carbonate. The covalent organic framework material includes reacted units of a 2,4,6-trimethyl-1,3,5-triazine, reacted units of a 4,4-biphenyldicarbaldehyde, and palladium nanoparticles. The reacted units of the 2,4,6-trimethyl-1,3,5-triazine and the reacted units of the 4,4-biphenyldicarbaldehyde form a COF-701, where the palladium nanoparticles are on an outer surface of the COF-701. The co-catalyst is n-tetrabutylammonium bromide.