Catalytic activity of nickel and cobalt for amination of ethylene glycol: Which is better?

• Metal Co is more suitable than Ni for amination of ethylene glycol. • The dissociation activation energies of O-H and C-H bond are lower on Co (0001) face. • The dissociation activation energies of C-C bond are smaller on Ni (111) face. • Metal Co is more suitable than Ni for amination of diols with short carbon chain. Metal Ni and Co are widely used in the catalytic amination of alcohols and Ni is more favored due to its better catalytic performance. Here we compared their catalytic performance for the amination of ethylene glycol and unexpectedly found that Co is more active than Ni. DFT calculation results showed that the energy barriers for the dissociation of O-H and C-H bond in an ethylene glycol molecule are smaller on Co (0001) plane, accounting for higher ethylene glycol conversion and primary amine yield on metal Co catalyst. The C-C bond dissociation in a glycolaldehyde (dehydrogenation intermediate of ethylene glycol) molecule has significantly lower energy barrier on Ni (111) plane, being consistent with lower selectivity of primary amine on metal Ni catalyst. We also compared their catalytic performance for the amination of other diols and the results showed that Co is more active when short-chain diols are used as the substrate.