Optimizing the Spatial Density of Single Co Sites via Molecular Spacing for Facilitating Sustainable Water Oxidation

Advances in single-atom (-site) catalysts (SACs) provide a new solution of atomic economy and accuracy for designing efficient electrocatalysts. In addition to a precise local coordination environment, controllable spatial active structure and tolerance under harsh operating conditions remain great challenges in the development of SACs. Here, we show a series of molecule-spaced SACs (msSACs) using different acid anhydrides to regulate the spatial density of discrete metal phthalocyanines with single Co sites, which significantly improve the effective active-site numbers and mass transfer, enabling one of the msSACs connected by pyromellitic dianhydride to exhibit an outstanding mass activity of (1.63 +/- 0.01) x 10(5) A.g(-1) and TOFbulk of 27.66 +/- 1.59 s(-1) at 1.58 V (vs RHE) and long-term durability at an ultrahigh current density of 2.0 A.cm(-2) under industrial conditions for oxygen evolution reaction. This study demonstrates that the accessible spatial density of single atom sites can be another important parameter to enhance the overall performance of catalysts.

Automated summary

Advances in single-atom catalysts provide a new solution for designing efficient electrocatalysts. This study demonstrates the use of molecule-spaced single-atom catalysts to significantly improve the active-site numbers and mass transfer. One of the molecule-spaced single-atom catalysts exhibits outstanding mass activity and long-term durability under industrial conditions for oxygen evolution reaction.