Design of Copper-Based Bimetallic Nanoparticles for Carbon Dioxide Adsorption and Activation

Cu-based nanoparticles (NPs) are promising candidates for the catalytic hydrogenation of CO₂ to useful chemicals because of their low cost. However, CO₂ adsorption and activation on Cu is not feasible. In this work we demonstrate a computational framework that identifies Cu-based bimetallic NPs able to adsorb and activate CO₂ based on DFT calculations. We screen a series of heteroatoms on Cu-based NPs based on their preference to occupy a surface site on the NP and to adsorb and activate CO₂ . We revealed two descriptors for CO₂ adsorption on the bimetallic NPs, the heteroatom (i) local d-band center and (ii) electropositivity, which both drive an effective charge transfer from the NP to CO₂ . We identified the CuZr bimetallic NP as a candidate nanostructure for CO₂ adsorption and showed that although the Zr sites can be oxidized because of their high oxophilicity, they are still able to adsorb and activate CO₂ strongly. Importantly, our computational results are verified by targeted synthesis, characterization, and CO₂ adsorption experiments that demonstrate that i) Zr segregates on the surface of Cu, ii) Zr is oxidized to form a bimetallic mixed CuZr oxide catalyst, which iii) can strongly adsorb CO₂ , whereas Cu NPs cannot. Overall our work highlights the importance of the generation of binding sites on a NP surface based on (catalyst) stability and electronic structure properties, which can lead to the design of more effective CO₂ reduction catalysts.