Water oxidation with transition metal catalysts with non-innocent ligands and its mechanisms

Water oxidation at low potential exploiting a nitroxide/oxoammonium ion redox couple as mediator

“…1a shows the initial continuous-wave cw-EPR spectrum of 3-CP (blue line). It is typical of an NitR, with three resolved lines due to the hyperfine splitting of the 14 N atom (I = 1) of the nitroxide. It is also possible to distinguish a further splitting of the lines due to 13 C (I = 1/2) in natural abundance.…”

“…12 Both heterogeneous and homogeneous molecular electrocatalysts based on transition metals are widely used for water oxidation to O 2 . 13,14 Also, metal-free catalysts based on carbon materials have been widely investigated for water oxidation. 15 In general, oxidation of water on these catalysts requires potentials that are significantly higher than the equilibrium potential of the H 2 O/O 2 redox couple.…”

Strategies for Electrochemically Sustainable H2 Production in Acid

“…Binuclear metal catalysts, such as binuclear Ru or Mn catalysts, can catalyze the OER via the 12M approach. [ 39 ] Scaling relations exist in these OER steps, which makes it difficult to optimize the adsorption of these intermediates simultaneously, leading to an inefficient OER. [ 27 ] As for the LOEM, the lattice oxygen in the electrocatalysts can directly participate in the OER, with the formation of possible intermediates *OO and *OH.…”

“…As alternative metals, Ru, Ir, Co, Mn, Fe, Ni, and Cu are highly active species for homogeneous OER. [ 39 , 148 , 165 , 166 ] However, many of these competent molecular catalysts, [ 167 , 168 , 169 , 170 , 171 ] e.g., the most typical homogeneous Cu complexes, [ 165 ] are usually tested under neutral or alkaline conditions, making them inappropriate for SHP in acidic media. In 2017, a soluble Mn cluster was reported by Maayan et al.…”

Perspectives of Redox-Active Ligands in Artificial Photosynthesis

“…The same review paid attention to structural mimics and brie y discussed the possible effects of redox active ligands on a catalytic process in general. Another excellent work categorized molecular transition metal OER catalysts as mono-and binuclear complexes, containing redox non-innocent ligands, and emphasized their role in supplying electrons or binding protons at different stages of the corresponding WNA or I2M mechanism, leading to a more e cient reaction (Sutradhar et al 2021).…”