Electrocatalytic hydrogen evolution with gallium hydride and ligand-centered reduction

摘要

Ga ~(III) chloride tetrakis(pentafluorophenyl)porphyrin ( 1 ) was synthesized and shown to be a highly active and stable post-transition metal-based electrocatalyst for the hydrogen evolution reaction (HER). Electrochemical and spectroscopic studies indicate that both the first and second reduction events of 1 are ligand-centered. The 2e-reduced form 1 ~(2?) reacts with a proton to give Ga ~(III) –H species ( 1 –H), which undergoes protonolysis with Br?nsted acids to produce H _(2) . The identification of key intermediates 1 ~(?) , 1 ~(2?) , and 1 –H leads to a catalytic cycle, which is valuable for the fundamental understanding of the HER. This study presents a rare but highly active HER electrocatalyst with unusual features, including ligand-centered electron transfer and formation of post-transition metal hydride.