Langerman Michiel, Hetterscheid Dennis G H
Leiden Institute of Chemistry, Leiden University, Gorlaeus Laboratories, P.O Box 9502, 2300, RA, Leiden, The Netherlands.
Angew Chem Int Ed Engl. 2019 Sep 9;58(37):12974-12978. doi: 10.1002/anie.201904075. Epub 2019 Jul 24.
Catalytic pathways for the reduction of dioxygen can either lead to the formation of water or peroxide as the reaction product. We demonstrate that the electrocatalytic reduction of O by the pyridylalkylamine copper complex [Cu(tmpa)(L)] in a neutral aqueous solution follows a stepwise 4 e /4 H pathway, in which H O is formed as a detectable intermediate and subsequently reduced to H O in two separate catalytic reactions. These homogeneous catalytic reactions are shown to be first order in catalyst. Coordination of O to Cu was found to be the rate-determining step in the formation of the peroxide intermediate. Furthermore, electrochemical studies of the reaction kinetics revealed a high turnover frequency of 1.5×10 s , the highest reported for any molecular copper catalyst.
将双氧还原的催化途径可能会导致反应产物生成水或过氧化物。我们证明，吡啶基烷基胺铜配合物[Cu(tmpa)(L)]在中性水溶液中对O的电催化还原遵循逐步的4e⁻/4H⁺途径，其中H₂O₂作为可检测的中间体形成，随后在两个单独的催化反应中还原为H₂O。这些均相催化反应显示为对催化剂呈一级反应。发现O与Cu的配位是过氧化物中间体形成中的速率决定步骤。此外，对反应动力学的电化学研究揭示了1.5×10⁻³ s⁻¹的高周转频率，这是任何分子铜催化剂所报道的最高值。
