Hydrotalcite-Derived Cu_xMg_3-xAlO Oxides for Catalytic Degradation of n-Butylamine with Low Concentration NO and Pollutant-Destruction Mechanism

The degradation of volatile organic compounds (VOCs) with simultaneous removal of the secondary pollutant NO_x is a promising solution for catalytic elimination of nitrogen-containing VOCs (NVOCs). Herein, a series of mixed Cu_xMg_3-xAlO oxides were prepared and tested for selective catalytic oxidation of n-butylamine. The Cu content of the catalysts significantly impacted their performance. Cu_0.4Mg_2.6AlO exhibited the best catalytic activity, with 100% conversion of n-butylamine and 83% N₂ selectivity at 350 °C. The catalysts were characterized by NH₃-TPD, XPS, EPR, UV-vis, and H₂-TPR to reveal the structure-activity relationship. On the basis of DRIFTS results, the reaction mechanism of selective oxidation of n-butylamine was proposed. Additionally, selective catalytic reduction of NO with NH₃ was further tested using Cu_0.4Mg_2.6AlO to remove NO_x, which was generated after the selective oxidation process. By coupling selective catalytic oxidation of NVOCs with selective catalytic reduction of NO_x, it provides a new effective strategy to synergistically remove NVOCs and NO_x.