CO Oxidation to CO₂ on Uranium Dioxide Molecules through Intermediate O₂U(η¹-CO)

Abstract

Investigations on the reactions of uranium oxide molecules with CO offer new inspiration for the design of promising high-efficiency catalysts for CO activation using actinide materials. Herein, we contribute a combined matrix-isolation infrared spectroscopic and theoretical study of CO oxidation to CO 2 on uranium dioxide (UO 2 ) molecules in solid argon. The reaction intermediate O 2 U(η 1 -CO) is generated spontaneously at the bands of 1893.0, 870.6, and 801.3 cm −1 during codeposition and annealing. Upon the following irradiation, CO 2 is substantially produced by the consumption of O 2 U(η 1 -CO), indicating the catalytic conversion of CO to CO 2 through the intermediate O 2 U(η 1 -CO). In C 18 O isotopic substitution experiments, the yields of 16 OC 18 O convincingly confirm that one of the oxygen atoms in CO 2 derives from UO 2 . The reaction pathways are discussed based on the theoretical and experimental results.