Electrochemical hydrogenation of oxidized contaminants for water purification without supporting electrolyte

Electrocatalytic hydrogenation enables the efficient treatment of oxidized contaminants in water under mild conditions, but its application has been greatly hindered by the need for a supporting electrolyte and the large amounts of unsafe intermediate products. Here we report the development of a rhodium nanoparticle-modified palladium membrane electrochemical reactor (Rh NPs-PdMER) for the hydrogenation of oxidized contaminants in drinking water and industrial effluents. The Rh NPs-PdMER not only enabled the hydrogenation of 12 different oxidized contaminants to safe products with ≥99% conversion and ≥95% yield in water without a supporting electrolyte, but also required a very low operating voltage of only 1.4 V. The performance of the Rh NPs-PdMER can be attributed to the specific reactor configuration and the unique adsorbability of the hydrogenated intermediates of the oxidized contaminants to the Rh nanoparticles.