Highly selective electrochemical reduction of CO2 to HCOOH on a gallium oxide cathode

• Published in: Electrochemistry communications Vol. 43; pp. 95 - 97
• Main Authors: Sekimoto, Takeyuki, Deguchi, Masahiro, Yotsuhashi, Satoshi, Yamada, Yuka, Masui, Takekazu, Kuramata, Akito, Yamakoshi, Shigenobu
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.06.2014; Amsterdam Elsevier; New York, NY
• Subjects: Cathode; Chemistry; CO2 reduction; Electrochemistry; Electrolysis; Exact sciences and technology; Formic acid; Gallium oxide; General and physical chemistry; Kinetics and mechanism of reactions; Electrolysis; CO2 reduction; Cathode; Formic acid; Gallium oxide; Carbon dioxide; Single crystal; Inorganic compound; Gallium III Oxides; Electrodes; Chemical reduction; Cyclic voltammetry; Electrochemical reaction
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2014.03.023

We report on the high-selectivity electrochemical reduction of CO2 to formic acid (HCOOH) using conductive single-crystal Ga2O3. Single-crystalline Sn- or Si-doped Ga2O3 was manufactured using an edge-defined film-fed growth method. The stability of Ga2O3 was confirmed over fifty cyclic voltammetry cycles. In our electrolysis experiments, a Ga2O3 cathode selectively produced HCOOH with a Faradaic efficiency of over 80% by electrochemical reduction of CO2. A possible intermediate state is simulated based on density function theory. Our calculations show the so-called formate on Ga2O3 to be a possible intermediate state in the reaction from CO2 to HCOOH. •The stability of Ga2O3 cathode was confirmed over fifty cyclic voltammetry cycles.•Ga2O3 cathode selectively produced HCOOH with >80% of Faradaic efficiency.•Formate on Ga2O3 is a possible intermediate state in the reaction from CO2 to HCOOH.