First Application of Sn (IV) Corrole As Electrocatalyst in Hydrogen Evolution Reaction

In this paper, four post-transition metal tin corrole complexes bearing different numbers of cyano-substituents (1, 2, 3, 4) had been synthesized and characterized. In which tin corroles Sn-CDPC (1) and Sn-PBCC (2) are new compounds. Among four prepared tin corroles, Sn-TCPC complex (3) exhibits the best electrocatalytic HER performance in organic phase. Its icat/ip and the turnover frequency (TOF) reaches 13.12 and 25.6 h-1 in DMF when using trifluoroacetic acid (TFA) as the proton source. The TOF of Sn-CDPC complex (1) in acetonitrile/ water (V/V = 2/3) neutral water system is the highest (474.3 h-1) and may produce 4.7 mL H2 with in 1 h of electrolysis. Electrochemical testing showed that the HER undergoes E-ECEC pathway whether using strong acid or weak acid as a proton source in organic media. This work presents the first example of using tin corroles as the electrocatalyst in HER.