%0 Journal Article %A Khusnutdinova, Diana %A Wadsworth, Brian L. %A Flores, Marco %A Beiler, Anna M. %A Reyes Cruz, Edgar A. %A Zenkov, Yegor %A Moore, Gary F. %D 2018 %T Electrocatalytic Properties of Binuclear Cu(II) Fused Porphyrins for Hydrogen Evolution %U https://acs.figshare.com/articles/journal_contribution/Electrocatalytic_Properties_of_Binuclear_Cu_II_Fused_Porphyrins_for_Hydrogen_Evolution/7140359 %R 10.1021/acscatal.8b01776.s001 %2 https://acs.figshare.com/ndownloader/files/13142060 %K Electrocatalytic Properties %K turnover frequency %K X-ray photoelectron spectroscopies %K beta positions %K 2 000 000 %K near-unity Faradaic efficiency %K nonfused %K electrocatalyst %K macrocycle %K Structural characterization %K porphyrin %K substrate protons %K reduction process %K species %K design element %K Electrochemical characterization %K Binuclear %X Binuclear copper­(II) porphyrins in which two copper­(II) porphyrin macrocycles are doubly fused at the meso-beta positions are shown to be active electrocatalysts for the hydrogen evolution reaction (2H+ + 2e → H2). Structural characterization, including use of electron paramagnetic resonance and X-ray photoelectron spectroscopies, verifies the fused species contains two copper­(II) metal centers in its resting state. In comparison to the nonfused copper­(II) porphyrin complex, the fused species is reduced at significantly less applied bias potentials (ΔE1/2 ∼ 570 mV for the first reduction process). Electrochemical characterization in the presence of substrate protons confirms the production of hydrogen with near-unity Faradaic efficiency, and kinetic analysis shows the catalyst achieves a maximum turnover frequency above 2 000 000 s–1. The enhancement in catalytic performance over analogous nonfused copper­(II) porphyrins indicates extended macrocycles provide an advantageous structural motif and design element for preparing electrocatalysts that activate small molecules of consequence to renewable energy. %I ACS Publications