MOF-coated catalyst converts CO₂ to CO nearly five times faster under ultrasonic vibration

Researchers at the University of Osaka have created a catalyst capable of converting carbon dioxide (CO2) into carbon monoxide (CO) under ultrasonic vibration, converting CO2 into CO nearly five times faster than pure barium titanate (BaTiO3). The catalyst, named Cu-ZIF-8/BT, consists of a BaTiO3 core coated with a metal-organic framework (MOF) called ZIF-8, which is hydrophobic and has a high capacity for adsorbing CO2.

The MOF shell contains isolated copper (Cu) atoms acting as reaction sites. When ultrasonic vibration is applied, the piezoelectric material converts mechanical energy into electrical charges, which are directed towards the Cu sites to drive the reaction. In water at room temperature without any additional chemicals, Cu-ZIF-8/BT generated CO at a rate of 114 μmol g-1 h-1, while BaTiO3 alone produced 24 μmol g-1 h-1 under the same conditions.

This indicates a 4.8-fold increase in CO production rate, approximately five times more efficient. The study suggests that close contact between the BaTiO3 core and Cu-ZIF-8 shell is crucial for enhancing the catalyst's performance. The research demonstrates an innovative approach to catalyst design, creating a local environment where reactants, reaction sites, and piezoelectric charges can interact more effectively.

This strategy could lead to more energy-efficient CO2 recycling methods and may also be applicable in other photocatalytic and electrocatalytic systems.