First Principles Calculations Combining Microkinetic Model for MXene Supported Single Atom Catalysts Screening and Designing
Li Sheng, Xiaomin Fu, Yanan Zhou, Xuan Wu, Weiyi Wang, Qunxiang Li, Wenhua Zhang, Jinlong YangABSTRACT
The dynamic co‐adsorption of possible intermediates on the single atom catalysts (SACs) under working conditions critically influences the mechanisms of oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). This work investigates oxygen vacancy site supported single atoms on MXene W 2 CO 2 (M 1 –W 2 CO 2 ) using density functional theory (DFT) and microkinetic simulations to reveal the effect of dynamic adsorption. The screening results differ significantly with and without considering this effect. Without dynamic adsorption, only Pt 1 ‐W 2 CO 2 (O v ) and Au 1 ‐W 2 CO 2 (O v ) are identified as OER and ORR SACs, respectively. When further considering single intermediate adsorption, more M 1 ‐W 2 CO 2 (O v ) are screened out as promising OER SACs such as Pt 1 (Rh 1 , Ni 1 )‐W 2 CO 2 (O v ), and ORR SACs such as Pt 1 (Ag 1 , Au 1 )‐W 2 CO 2 (O v ). The reason for the difference is the ΔG *OH with intermediates (*OH, *O) covered moves toward the optimal region of the volcano plot for ΔG L and ΔG *OH . Compared with uncovered case, the d‐band center of Pt 1 (Rh 1 , Ni 1 ) decreases with *OH covered, and adsorbate surface interaction weakens, which means ΔG *OH would increase. Considering multiple intermediates yields the same trend. This study highlights the importance of dynamic adsorption in theoretical screening and provides guidance for designing efficient single‐atom electrocatalysts for OER and ORR.