Sustainable high-energy radiation powering selective CO2 reduction to CH3OH over atomic dual-metal-sites embedded metal-organic framework

Abstract The efficient use of renewable high-energy radiation (X/γ-rays or accelerated e ‒ ) as the energy input for the chemical transformation of carbon dioxide (CO 2 ) and water to energy-rich fuels holds new promise for a carbon-neutral, sustainable energy economy; however, such processes are challenging to implement, and require the assistance of catalysts capable of sensitizing the secondary electron scattering and providing active metal sites to bind intermediates. Herein, we report that atomic Cu-Ni dual-metal-sites embedded in a metal-organic framework matrix enable efficient and selective (~ 98%) conversion of CO 2 to CH 3 OH in irradiated aqueous solutions. The reaction is initiated by the direct generation of CO 2 •‒ radicals via aqueous electrons attachment, followed by a series of interfacial reactions. We showed that the UiO-66(Hf) matrix serves as a radiation sensitizer to break electron yield limitation in water radiolysis, dramatically promoting CO 2 activation and conversion efficiency. With the synergistic metal centers and a hydroxyl radical scavenger, we achieved stable and selective CH 3 OH production over multiple irradiation cycles. Pulse radiolysis experiments with theoretical calculations revealed the transient kinetics occurred on the nanosecond timescale and cascade hydrogenation steps. Our study highlighted an unprecedented catalytic route to produce CH 3 OH with CO 2 feedstock and introduced a desirable atomic structure to improve performance.