Highly Efficient Solar‐Driven Carbon Dioxide Reduction on Molybdenum Disulfide Catalyst Using Choline Chloride‐Based Electrolyte

• Published in: Advanced energy materials 2019-03, Vol.9 (9), p.n/a
• Main Authors: Asadi, Mohammad, Motevaselian, Mohammad Hossein, Moradzadeh, Alireza, Majidi, Leily, Esmaeilirad, Mohammadreza, Sun, Tao Victor, Liu, Cong, Bose, Rumki, Abbasi, Pedram, Zapol, Peter, Khodadoust, Amid P., Curtiss, Larry A., Aluru, Narayana R., Salehi‐Khojin, Amin
• Format: Article
• Language: English
• Subjects: Buffer solutions; Carbon cycle; Carbon dioxide; Carbon monoxide; Catalysts; Catalytic converters; Choline; Conversion; Density functional theory; Electrolytes; flow cells; Livestock; Molybdenum; Molybdenum disulfide; Organic chemistry; photochemical; photoelectrochemical; Potassium hydroxides; Reaction mechanisms; Reduction; solar to fuel conversion; Water chemistry
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201803536

Conversion of CO2 to energy‐rich chemicals using renewable energy is of much interest to close the anthropogenic carbon cycle. However, the current photoelectrochemical systems are still far from being practically feasible. Here the successful demonstration of a continuous, energy efficient, and scalable solar‐driven CO2 reduction process based on earth‐abundant molybdenum disulfide (MoS2) catalyst, which works in synergy with an inexpensive hybrid electrolyte of choline chloride (a common food additive for livestock) and potassium hydroxide (KOH) is reported. The CO2 saturated hybrid electrolyte utilized in this study also acts as a buffer solution (pH ≈ 7.6) to adjust pH during the reactions. This study reveals that this system can efficiently convert CO2 to CO with solar‐to‐fuel and catalytic conversion efficiencies of 23% and 83%, respectively. Using density functional theory calculations, a new reaction mechanism in which the water molecules near the MoS2 cathode act as proton donors to facilitate the CO2 reduction process by MoS2 catalyst is proposed. This demonstration of a continuous, cost‐effective, and energy efficient solar driven CO2 conversion process is a key step toward the industrialization of this technology. An efficient and scalable solar‐driven CO2 reduction process is reported based on an MoS2 catalyst and an inexpensive hybrid electrolyte of choline chloride and KOH. A maximum solar to fuel and catalytic conversion efficiencies of 23% and 83% are obtained, respectively. This demonstration of solar‐driven CO2 conversion process is a key step toward the industrialization of this technology.