Electrocatalytic CO Upgrading to Triethanolamine by Bromine-Assisted C H Oxidation.

The electrocatalytic carbon dioxide (CO ) reduction is a promising approach for converting this greenhouse gas into value-added chemicals, while the capability of producing products with longer carbon chains (C >3) is limited. Herein, we demonstrate the Br-assisted electrocatalytic oxidation of ethylene (C H ), a major CO electroreduction product, into 2-bromoethanol by electro-generated bromine on metal phthalocyanine catalysts. Due to the preferential formation of Br over *O or Cl to activate the C=C bond, a high partial current density of producing 2-bromoethanol (46.6 mA⋅cm ) was obtained with 87.2 % Faradaic efficiency. Further coupling with the electrocatalytic nitrite reduction to ammonia at the cathode allowed the production of triethanolamine with six carbon atoms. Moreover, by coupling a CO electrolysis cell for in situ C H generation and a C H oxidation/nitrite reduction cell, the capability of upgrading of CO and nitrite into triethanolamine was demonstrated.