Unraveling the origin of high-efficiency performance of CeCu bimetallic quasi-MOFs catalysts for the selective catalytic reduction of NO by CO

Abstract

The selective catalytic reduction of NO_x by CO (CO-SCR) offers an effective solution for removing CO and NO in the steel industry without requiring additional reductants. In this study, CeCu-BTC bimetallic MOF precursors were synthesized via solvothermal methods, followed by partial pyrolysis to prepare quasi-CeCu-BTC catalysts. Among these, Ce1Cu4-BTC-350 exhibited the best catalytic performance, achieving 100 % NO_x conversion and 90 % CO conversion at 275℃. Remarkably, Ce1Cu4-BTC-350 maintained 100 % NO_x conversion and 93.5 % CO conversion even in the presence of 15000 ppm O₂, while the addition of H₂O mitigated the poisoning effect of SO₂. Partial pyrolysis improved the accessibility of active sites and optimally preserved the porous structure of the MOF materials. The synergistic interaction between Cu and Ce enhanced the proportion of adsorbed oxygen on the catalyst surface, improved redox properties, and increased the abundance of reduced species. DFT and experimental results demonstrated a significant improvement in the adsorption capacity of reactive gases by the catalyst. The CO-SCR reaction followed the Langmuir-Hinshelwood mechanism, with *N₂O₂ identified as a critical intermediate. DFT further revealed that the adsorption of CO after the formation of *N₂O₂ is the step with the highest energy barrier.