Two Dimensional Ferroelectric-Based Catalysts for Enhanced CO₂ Reduction

The electrochemical CO₂ reduction reaction (CO2RR), which can turn CO₂ into to C1 and C2 products, has been proposed as a route to both combat global warming and produce value-added fuels; however, a lack of efficient catalysts is limiting its implementation. Recently, single atom and dual atom catalysts (SACs and DACs, respectively), have been shown to enhance the CO2RR but still suffer from scaling relationships limits. In this work, we show that 2D ferroelectric (2DFE) materials, which display a spontaneous electric polarization in a single monolayer that is switchable by an applied electric field, can be used to overcome limiting scaling relationships and break the Sabatier principle, leading to enhanced CO2RR propensity. We first show that the predicted 2DFE MXene Y₂CO₂ with an O vacancy can preferentially adsorb CO₂ or CO. We then investigated the reduction CO₂ to various C1 products (e.g., methanol, formic acid, etc.) and find that switching the direction of the polarization changes the shape of the reaction pathway. Second, we investigated the CO2RR on SAC and DAC-doped graphene interfaces with the 2DFE In₂Se₃. In this case, the reduction of CO₂ to CO is greatly enhanced compared to the free standing doped graphene layer regardless of the SAC/DAC coordination environment. In both systems, the asymmetry in the surface electron density allows for the tuning of surface adsorption and intermediate stability, as well as activation of alternative pathways. By combining the catalytic properties of 2D-support SACs and DACs with the switchable polarization of 2DFEs, such heterostructures can exhibit higher efficiency and selectivity for CO2RR than existing catalysts and provides a unique route to overcome these issues.