Diving into the influence of phosphorus on ceria-supported copper manganese bimetallic oxides for catalytic removal of carbon monoxide

The application of ceria-supported catalysts as promising catalysts for air pollutant abatement via heterogeneous catalytic processes is still a challenge. Phosphorus (P) is a potential threat to catalyst deactivation but has not been sufficiently explored. Herein, a systematic study reveals the poisoning behaviors of P on Cu-Mn bimetallic oxides supported by ceria (Cu-Mn/CeO 2 ) as a typical case in CO oxidation and provides new insights into the deactivation mechanism. The P impregnation decreases the surface area of Cu-Mn/CeO 2 and leads to the emergence of a new sheet morphology. The interactions between P and catalyst components (support and active species) result in the generation of dominant P species of PO 4 3− and PO 3 − . The P addition also weakens the oxygen storage capacity of ceria and decreases the proportions of low-valent Cu and Mn, hindering electron transfers among metals. Furthermore, the reducibility and the adsorption and activation of O 2 are limited in P-loaded Cu-Mn/CeO 2 catalysts as found in H 2 -TPR and O 2 -TPD when increasing the P concentration. In situ DRIFTS experiments demonstrate that the inhibition of the formation and transformation of active intermediates, namely carbonyls and carbonates, is responsible for the poisoning behaviors of P in the pathway of CO oxidation over Cu-Mn/CeO 2 catalyst.