First-principles and experimental studies of [ZrO(OH)]+ or ZrO(OH)2 for enhancing CO2 desorption kinetics – imperative for significant reduction of CO2 capture energy consumption

Abstract

The most formidable challenge in each CO₂ capture technology lies in its high energy consumption, which mainly results from slow CO₂ desorption kinetics in every chemisorption-based CO₂ capture process. This can be overcome by using catalysis. This research was designed to study the catalytic performance of [ZrO(OH)]⁺ resulting from the surface hydrolysis of ZrO₂ on CO₂ desorption with the decomposition of KHCO₃ supported by ZrO₂ and Al₂O₃ or KHCO₃/ZrO₂/Al₂O₃ by using experiments based on density functional theory (DFT) and thermogravimetric analysis (TGA). Computations show that H₂O is substantially better than CO₂ for adsorption on monoclinic ZrO₂ (001) surface and intermediate [ZrO(OH)]⁺ and OH⁻, which results from the adsorption of H₂O on the catalyst ZrO₂ surface, and it can significantly accelerate the dissociation of HCO₃⁻. This can reduce the energy required for CO₂ capture. Furthermore, the catalysis function of [ZrO(OH)]⁺ predicted using computations was successfully confirmed with TGA and X-ray photoelectron spectroscopy (XPS) tests.