Control of the substituent at the nitrogen atom in a 2,4,6-triphenylpyridinium perchlorates tunes the electrocatalytic hydrogen evolution mechanism and efficiency

Abstract Electrochemical properties and electrocatalytic activity in of hydrogen evolution reaction (HER) in new members of the family of homogeneous organic metal-free catalysts based on N-methyl and N-phenyl - 2,4,6-triphenylpyridinium perchlorates were studied using electrochemical methods. With a similar structure and electrochemical properties, the electrocatalytic behavior differs dramatically. The main reason for this is the “nature” of the substituent in the nitrogen atom. It is shown for the first time that by varying the potential of the electrocatalytic process, it is possible to control the mechanism (switch) and the efficiency of the process. Foot-of-the-wave analysis (FOWA) was performed to measure the kinetics of the process. The calculated value of kobs = 155.2 s−1 for N-methyl-2,4,6-triphenylpyridinium perchlorate is a record among all homogeneous metal-free electrocatalysts.