Strategies for Regulating the Activity, Selectivity, and Durability of Cu-Based Catalysts for CO2 Reduction

The excessive use of fossil resources has led to a rapid increase in the greenhouse gas carbon dioxide (CO₂) level in the atmosphere. In order to curb the harmful consequences of global warming, it is urgent to develop effective CO₂ conversion technologies.

The electroreduction CO₂ reaction (CO₂RR), using green electricity and low-cost water as the proton source, is a promising solution to convert CO₂ into valuable fuels or chemicals. Its successful implementation will reduce greenhouse gas emissions and also develop a fossil-independent chemical industry.

However, CO₂ is a non-polar linear molecule with strong bond energy, making it difficult to activate. It often requires a large overpotential and encounters severe hydrogen evolution side reaction. In addition, the CO₂RR products are varieties of C₁ to C₄ hydrocarbons and oxygenates.

High overpotential and low selectivity lead to a poor CO₂RR energy conversion efficiency. Developing a catalyst with high activity and selectivity (especially toward a single product) is a prerequisite for the high-efficiency CO₂RR conversion.

Copper (Cu) is the only monometallic catalyst that can produce carbon monoxide (CO), formic acid/formate (HCOOH/HCOO⁻), and deep-reduced products such as methane (CH₄), ethylene (C₂H₄), and ethanol (C₂H₅OH). However, its activity, selectivity, and durability are still far from meeting practical application needs. Prof. L. Zhuang and colleagues in Wuhan University reviewed the recent progress of Cu-based catalysts, focusing on the effective strategies for improving the activity, selectivity, and durability of Cu-based catalysts.

These strategies can be divided into two categories: tuning the surface atomic/electronic structures and regulating the local physical/chemical environment. This review first summarized the successful implementation of these strategies in promoting different products formation, followed by the reasons for Cu-based catalysts' deactivation and the potential solutions. It may help to outline the current challenges and future opportunities in this field.

Source: https://phys.org/