Electrocatalytic Reduction of CO<sub>2</sub> to Ethylene by Molecular Cu‐Complex Immobilized on Graphitized Mesoporous Carbon
Mani Balamurugan, Hui‐Yun Jeong, Venkata Surya Kumar Choutipalli, Jung Sug Hong, Hongmin Seo, Natarajan Saravanan, Jun Ho Jang, Kang‐Gyu Lee, Yoon Ho Lee, Sang Won Im, V. Subramanian, Sun Hee Kim, Ki Tae Nam
Abstract
Abstract The electrochemical reduction of carbon dioxide (CO 2 ) to hydrocarbons is a challenging task because of the issues in controlling the efficiency and selectivity of the products. Among the various transition metals, copper has attracted attention as it yields more reduced and C2 products even while using mononuclear copper center as catalysts. In addition, it is found that reversible formation of copper nanoparticle acts as the real catalytically active site for the conversion of CO 2 to reduced products. Here, it is demonstrated that the dinuclear molecular copper complex immobilized over graphitized mesoporous carbon can act as catalysts for the conversion of CO 2 to hydrocarbons (methane and ethylene) up to 60%. Interestingly, high selectivity toward C2 product (40% faradaic efficiency) is achieved by a molecular complex based hybrid material from CO 2 in 0.1 m KCl. In addition, the role of local pH, porous structure, and carbon support in limiting the mass transport to achieve the highly reduced products is demonstrated. Although the spectroscopic analysis of the catalysts exhibits molecular nature of the complex after 2 h bulk electrolysis, morphological study reveals that the newly generated copper cluster is the real active site during the catalytic reactions.