2023/04/26 by Hao Chen, Chen, Hao, Lorenz J. Falling +23
Chemical Engineering · Chemistry · Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #Catalysis #Catalysis and Oxidation Reactions #Catalytic Processes in Materials Science #Chemical Physics (physics.chem-ph) #Chemical engineering #Chemistry #FOS: Physical sciences #Inorganic chemistry #Materials Science (cond-mat.mtrl-sci) #Materials science #Organic chemistry #Oxide #Oxygen #Phase (matter) #Physical chemistry #Redox #Stoichiometry #X-ray photoelectron spectroscopy
paper · pdf · doi:10.48550/arxiv.2304.13859
openalex publication_date 2023/04/26 · openalex created_date 2023/04/30 · openalex updated_date 2026/07/28
Using CoOx thin films supported on Au(111) single crystal surfaces as model catalysts for the CO oxidation reaction we show that three reaction regimes exist in response to chemical and topographic restructuring of the CoOx catalyst as a function of reactant gas phase CO/O2 stoichiometry a finding that highlights the versatility of catalysts and their evolution in response to reaction conditions. Under oxygen-lean conditions and moderate temperatures (below 150C degrees) partially oxidized films containing CoO were found to be efficient catalysts. In contrast, stoichiometric CoO films containing only Co2+ form carbonates in the presence of CO that poison the reaction below 300 C degrees. Under oxygen-rich conditions a more oxidized catalyst phase forms containing Co3+ species that is effective in a wide temperature range. Resonant photoemission spectroscopy (ResPES) revealed the unique role of Co3+ sites in catalyzing the CO oxidation. DFT calculations provided deeper insights into the pathway and free energy barriers for the reactions on these oxide phases.