Boosting NO removal performance of selective catalytic reduction with NH3 on hydrotalcite derived NiCuFe mixed oxides synthesized via urea hydrothermal method

NiCuFe layered double oxide (LDO) catalysts were synthesized using co-precipitation, impregnation, and urea hydrothermal methods. The NH3-SCR activity of NiCuFe-LDO catalysts was investigated to determine the effect of different synthesis methods. All NiCuFe-LDO samples exhibited good catalytic performance at low temperatures, with the sample synthesized using the urea hydrothermal method (NiCuFe-LDO-3) being the most efficient catalyst. The NiCuFe-LDO-3 catalyst achieved over 80% NO conversion in the temperature range of 180(degrees)C to 280 C-degrees, with a peak of 95.13% at 240(degrees)C. The physicochemical properties of the samples were systematically characterized using XRD, SEM, BET, NH3-TPD, H-2-TPR, XPS, and in-situ DRIFTS. The results showed that the NiCuFe-LDO-3 sample had the best crystallinity, as demonstrated by XRD and SEM. BET analysis revealed that the NiCuFe-LDO-3 sample had the largest specific surface area. The NiCuFe-LDO-3 sample was found to have more acidic sites and a better redox capacity than the other samples, according to the H-2-TPR and NH3-TPD results. In-situ DRIFTS analysis showed that the catalyst operates through both E-R and L-H reaction mechanisms.