Suppressed CO disproportionation with Cu-O-Ti bonds for nearly 100% synchronous removal of NO with CO

This study focuses on the severe hazards of nitrogen oxides (NO x ) to the environment and human health, and explores the selective catalytic reduction of NO (CO-SCR) technology based on water-washed mica-derived layered double oxides (LDOs). Although CuAl-LDO has certain potential in this reaction, its activity is still limited, and there is a problem of asynchronous conversion of CO and NO. Therefore, this paper designs a Ti-doped CuAl-LDO catalyst, which is successfully synthesized by the co-precipitation combined with calcination method. Performance tests show that Ti doping significantly enhances the CO-SCR activity of the catalyst and the conversion of CO and the reduction of NO achieve good synchronization. Mechanism studies indicate that the introduction of Ti induces the formation of a Cu-O-Ti interface structure, promotes electron transfer between Cu and Ti sites, enhances the redox cycling ability, and strengthens the adsorption and dissociation processes of NO. Through pure CO atmosphere tests, In situ Fourier transform infrared spectroscopy ( In situ FTIR), and density functional theory (DFT) calculations, it is further confirmed that Ti doping effectively inhibits the CO disproportionation reaction. The Cu-O-Ti interface helps to stabilize the formation of the key reaction intermediate Cu + -CO and significantly reduces the energy barrier of NO reduction. The catalyst remains stable under continuous operation at 400 °C for 30 h, and the N 2 selectivity always remains above 95%. This study provides a new design idea and theoretical basis for developing efficient and stable CO-SCR catalysts through precise interface engineering strategies. • Cu-O-Ti interface suppresses CO disproportionation, synchronizing NO/CO removal. • Ti-doped CuAl-LDO achieves 100% NO & CO conversion at 400 °C with >95% N 2 selectivity. • In situ Fourier transform infrared spectroscopy and DFT calculations indicate that Cu-O-Ti stabilizes Cu + -CO intermediate.