A highly active copper catalyst for the hydrogenation of carbon dioxide to formate under ambient conditions

Abstract

Carbon dioxide (CO₂) is an important reactant and can be used for the syntheses of various types of industrially important chemicals. Hence, investigation concerning the conversion of CO₂ into valuable energy-rich chemicals is an important and current topic in molecular catalysis. Recent research on molecular catalysts has led to improved rates for conversion of CO₂ to energy-rich products such as formate, but the catalysts based on first-row transition metals are underdeveloped. Copper(I) complexes containing the 1,1′-bis(di-tert-butylphosphino) ferrocene ligand were found to promote the catalytic hydrogenation of CO₂ to formate in the presence of DBU as the base, where the catalytic conversion of CO₂via hydrogenation is achieved using in situ gaseous H₂ (granulated tin metal and concentrated HCl) to produce valuable energy-rich chemicals, and therefore it is a promising, safe and simple strategy to conduct reactions under ambient pressure at room temperature. Towards this goal, we report an efficient copper(I) complex based catalyst [CuI(dtbpf)] to achieve ambient-pressure CO₂ hydrogenation catalysis for generating the formate salt (HCO₂⁻) with turnover number (TON) values of 326 to 1.065 × 10⁵ in 12 to 48 h of reaction at 25 °C to 80 °C. The outstanding catalytic performance of [CuI(dtbpf)] makes it a potential candidate for realizing the large-scale production of formate by CO₂ hydrogenation.