Efficient Electrocarboxylation Of Polycyclic Aromatic Hydrocarbon With Carbon Dioxide

In this paper, a simple and efficient electrochemical route has been developed for the electrocarboxylation of CO₂ Bwith polycyclic aromatic hydrocarbons. Using Ni cathode and Al sacrificial anode, the electrocarboxylation of polycyclic aromatic hydrocarbons (naphthalene, 5-methylnaphthalene, anthracene, phenanthrene and 1H-indene) with carbon dioxide (4 MPa) could be successfully performed in an undivided cell containing n-Bu4NBr–DMF supporting electrolyte with a constant current at room temperature, affording the corresponding trans-dicarboxylic acids in good to excellent yields (62%?90%). Among the examined cathode materials (Ni, Pt, Ag, Fe, Cu, Zn and Cu-Sn alloy), only Ni and Pt cathodes could realize the electrocarboxylation reactions, showing that Ni and Pt not only act as cathodes but also as catalysts for the electrocarboxylations. In addition, the experimental results indicated that electrolysis conditions (conducting salts, electricity, CO₂ pressure and temperature) also affect the result of the electrocarboxylation.We also investigated the electrochemical reaction mechanism of CO₂ with polycyclic aromatic hydrocarbons. According to the results of CV and the electrocarboxylations, a possible electrochemical reaction mechanism was proposed.