Formaldehyde oxidation on Co-doped reduced CeO2(111): First-principles calculations

Catalytic oxidation is most promising among various possible ways of removal of Formaldehyde (HCHO). Here, DFT + U calculations have been utilized to explore theoretically three potential pathways of HCHO oxidation on Co doped reduced CeO2(111). Formation oxygen vacancy formation energies are calculated on developed CoxCe1-xO2(111) p(4 x 4) surface. Chemisorbed and physisorbed configurations of HCHO are both explored, where the most stable adsorption mode on CoxCe1-xO2(111) is comparable with previous reports by dioxymethylene configuration. Based on Langmuir-Hinshelwood mechanism in which O-2 and HCHO are both co-adsorbed on the defective CoxCe1-xO2-delta(111) surface, resultant reaction products from three different initial HCHO co-adsorption modes with O-2, are identified finally in detail within the frame of transition state theory. We predict that the reaction pathway of HCHO to CO proceeds with the lowest overall barrier on defective Co-doped CeO2(111). These findings provide clear insight into further exploration in formaldehyde activation processes.