Catalysts for electrochemical CO₂ conversion: material sustainability perspective

The electrochemical reduction of CO₂ (eCO₂R) presents a promising pathway for addressing climate change by converting CO₂ into value-added chemicals and fuels. A crucial aspect of this technology is the choice of catalyst materials, which directly influences the selectivity, stability and sustainability of the process. Here we introduce a streamlined supply risk assessment coupled with life-cycle environmental impact associated with various catalysts used in eCO₂R for products, including formate, carbon monoxide, ethylene, and ethanol to provide a well-rounded perspective for catalysts' sustainability assessment. We compare more than 68 case studies in eCO₂R using various metal-based catalysts. Our results show that Bi-based catalysts for formate production have the highest supply risk and environmental burdens, while Sn-based catalysts show overall better durability and much lower sustainability concerns. Copper-based catalysts' supply risk for ethylene conversion is lower and more concentrated, whereas the supply risk for ethanol conversion is more dispersed. Our findings further confirm that improving catalyst performance-especially the stability-can substantially mitigate both supply risks and environmental impacts. This highlights the urgent need for standardized methodologies to assess catalyst stability and novel strategies to further improve catalyst stability using both material and system approaches. We call for stronger cross-sector collaboration to further integrate criticality and sustainability assessment frameworks with more granular datasets and dynamic spatial and temporal representation, for continuous eco-design improvement of eCO₂R catalysts.