Laccase Mimics: Probing the Electrocatalytic Potential for CO₂ Reduction

The intricate copper-based redox center in laccase serves as an exemplar for developing laccase mimics. The current need of the hour is exploring the application of these biogenic laccase mimics beyond their traditional roles in sustainable energy conversion. This study investigates the untapped potential of laccase and their biogenic copper-amino acid mimic in the context of electrochemical CO₂ reduction (ECR), leveraging the Cu²⁺/Cu¹⁺ redox system. The mimics demonstrated outstanding catalytic efficiencies relative to laccase. The functional coherence is further confirmed by catalytic decolorization ability towards azo and triphenylmethane dyes, indicating their oxidative nature akin to laccase. Furthermore, this study highlights the exceptional performance of the F-Cu (phenylalanine-copper) mimic in CO₂ electroreduction, accomplishing an ECR yield rate of 35 ± 1.2 µmol cm⁻² mg⁻¹ h⁻¹, which notably exceeds that of the enzyme, a result attributed to copper's established effectiveness and the ability of amino acid ligands to tune the catalytic activity and selectivity. This study highlights the strategic use of laccase analogues as electrocatalysts, bridging the gap between biocatalytic versatility and practical utility in sustainable applications.