2026/07/16 by Tarek Ayadi, Mourad Debbichi, Michael Badawi +3
#cond-mat.mtrl-sci
Using a combination of static and dynamic density functional theory simulations, we systematically investigated how phosphorus doping and oxygen vacancies on the CeO2(111) surface influence the oxidation mechanisms of formaldehyde (HCHO). Our results reveal that P cations (P5+) substitutionally replace Ce4+ in the lattice, forming Ce-O-P bonds that reduce the band gap (from 2.26 eV to 2.09 eV) and generate localized Ce3+ states through charge redistribution. This synergistic effect of P doping combined with oxygen vacancy strengthens HCHO adsorption by decreasing the adsorption energy from -0.62 eV on pristine CeO2(111) to -2.65 eV on the defective P-doped surface. Importantly, P doping lowers the C-H bond cleavage barrier by 0.84 eV relative to pristine CeO2(111), accelerating formaldehyde oxidation on the defective surface. In addition, the rapid desorption of CO2 and H2O (τ∼ 0.59 s at 300 K) indicates weak product-surface interactions, which favor efficient catalyst regeneration during continuous operation. These findings highlight P-doped CeO2(111) as a promising system for low-temperature HCHO oxidation and provide insights into the design of ceria-based catalytic materials.