Harvesting surface charges on metals for energy-efficient CO2 capture: A first-principles investigation

The CO2 capture industry predominantly relies on energy-intensive liquid amine solutions for capturing carbon dioxide, resulting in reduced efficiency and increased costs during regeneration. In response, we investigate the potential of surface charges induced by various stimuli (e.g., sunlight and voltage) on metal surfaces as an energy-efficient alternative for CO2 capture. This study employs density-functional theory calculations to examine the interaction between CO2 molecules and a diverse set of metal surfaces under varying charge conditions, encompassing both plasmonic and non-plasmonic transition metals, including Cu, Zn, Co, Fe, V, Pt, Ni, and Al. Our objective is to comprehensively understand how surface charges impact CO2 adsorption and desorption processes. Key factors under investigation include CO2 adsorption energy, the d-band center of pristine metal surfaces, surface charge distributions, and structural changes in CO2 upon adsorption. Our findings emphasize that the d-band center of metal surfaces is an insufficient descriptor for CO2 adsorption and desorption. Different metals exhibit distinct behaviors in response to surface conditions when it comes to CO2 adsorption and desorption. Specifically, this study concludes that the metals that display optimum CO2 adsorption and desorption efficiency include Cu, Zn, Co(alpha), and Al(beta). CO2 adsorption on these metal surfaces occurs under neutral conditions, while desorption takes place in electron-rich or electron-deficient conditions. These findings have implications for future experimental studies aiming to manipulate CO2 interactions with neutral or charged metal surfaces, potentially driving innovative advancements in CO2 capture technologies.