(365d) Catalyzed Activation of CO2 by Lewis Base Site in Hybrid Metal Organic Frameworks

Activation of carbon dioxide (CO₂) is a crucial and challenging step in recycling CO₂ as a source of carbon to produce useful chemicals, because CO₂ is an inert and thermodynamically stable compound. In this work, a metal-organic framework (MOF)-based catalyst W-Cu-BTC is designed by hybridizing highly active W atoms into the Cu-BTC frameworks based on density functional (DFT) calculations. We show that the hybrid W-Cu node plays a pivotal role in activating CO₂ according to the frontier molecular orbital theory. In contrast to the Lewis acid nature of open metal sites in most MOFs, the exposed W ion in W-Cu-BTC is identified as a Lewis base site, evidenced by the substantial electron donation from W ion to CO₂. Kinetically, the linear CO₂ molecule can be readily bent by forming a CO₂-W complex after overcoming a negligible activation barrier of 0.09 eV. In addition, we present calculated infrared spectra (IR) and X-Ray spectra (XPS) for reference in future experimental studies.