(Invited) Highly Selective and Efficient Conversion of CO_2 to Fomate and Oxalate

摘要

We succeeded in fabricating a dental amalgam composition on a copper foam electrode and could convert CO_2 selectively to formate. The formate could be produced at a current efficiency of 80～100% in a wide range of the potential of 0.6 V. The remaining electricity was used only for producing H_2. The concentration of the produced formate is over 1.2 M in the batch electrolysis of 30-hours operation. The CO_2-to-formate conversion system, built based on the electrode in the dimension of 9 cm × 9, is shown to be stable in continuous operation at 100 mA/cm~2 for more than a month. In the case of the conversion to oxalate, the electrolysis of CO_2 in an organic solvent with a sacrificial anode, the current efficiency of 95%, and the production of 80 g of the oxalate salt could be obtained for 18-hour electrolysis using the three-stack-cell electrolysis unit.