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.