Hydrophobic Trinuclear Copper Cluster-Containing Organic Framework for Synergetic Electrocatalytic Synthesis of Amino Acids

Electrocatalytic synthesis of amino acids provides a promising green and efficient pathway to manufacture the basic substances of life. Herein, reaction of 2,5-perfluroalkyl-terepthalohydrazide and tris(4-mu 2-O-carboxaldehyde-pyrazolato-N, N ')-tricopper affords a crystalline trinuclear copper cluster-containing organic framework, named F-Cu3-OF. Incorporation of abundant hydrophobic perfluroalkyl groups inside the channels of F-Cu3-OF is revealed to successfully suppress the hydrogen evolution reaction via preventing H+ cation with large polarity from the framework of F-Cu3-OF and in turn increasing the adsorption of other substrates with relatively small polarity like NO3- and keto acids on the active sites. The copper atoms with short distance in the trinuclear copper clusters of F-Cu3-OF enable simultaneous activization of NO3- and keto acids, facilitating the following synergistic and efficient CN coupling on the basis of in situ spectroscopic investigations together with theoretical calculation. Combination of these effects leads to efficient electroproduction of various amino acids including glycine, alanine, leucine, valine, and phenylalanine from NO3- and keto acids with a Faraday efficiency of 42%-71% and a yield of 187-957 mu mol cm-2 h-1, representing the thus far best performance. This work shall be helpful for developing economical, eco-friendly, and high-efficiency strategy for the production of amino acids and other life substances. The designed perfluoroalkyl hydrophobic crystalline trinuclear Cu-containing cluster organic frameworks not only inhibit hydrogen evolution reaction, but also the dynamic reconfiguration of the trinuclear Cu clusters in the F-Cu3-OF allows short-range Cu atoms to activate NO3- and keto acids at the same time and shows excellent performance in electrocatalytic CN coupling to generate a series of amino acids.image