Electrocatalytic activation of permanganate as a highly efficient advanced oxidation strategy for water purification

The permanganate (PM)-based advanced oxidation process is a promising water cleaning technology, but it is difficult to control the formation of reactive manganese species (RMnS). Here, we report a general strategy for the electrocatalytic activation of PM via the hydrogenation route to control the sequential formation of RMnS with high selectivity and efficiency. In this strategy, single-atom copper catalysts show superior electrocatalytic performance for the degradation of refractory organic pollutants and excellent stability. In contrast to the traditional electrochemical activation strategy, electrocatalytic PM activation is thermodynamically favorable with low energy consumption. Through theoretical calculations, in situ spectroscopy measurements, and physical experiments, we show that the activation of PM followed the electrocatalytic hydrogenation route, with electron transfer from atomic hydrogen (H∗) to PM following the pathway of s-orbital donation and t-orbital back-donation for the sequential generation of RMnS. This study opens up a model of PM activation applied to water purification.