Layered double hydroxides: Novel nanocatalysts for combustion of gaseous toluene from polluted air

The catalytic performance of NiAl, MgAl, and CoNi LDHs as novel nanocatalysts was evaluated in the oxidation of toluene. The samples were characterized by Xray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The XRD and FTIR approved the structure and functional groups of the LDH, respectively. Also, the presence of cations with different oxidation state confirmed by XRD. According to this result, Mars Van Krevelen (MVK) mechanism was suggested for the combustion of toluene over the LDH nanocatalysts. The SEM results indicated that the nanostructure and layered morphology of the catalysts. All LDHs exhibited catalytic activity for toluene oxidation. T80 (temperature for 80% conversion for toluene) for CoNi, NiAl and MgAl LDH catalysts were 225, 277 and 350 °C, respectively. So, the CoNi LDH showed the highest activity. Furthermore, NiAl LDH exhibited the highest thermal stability. So, we concluded that NiAl LDH is a superior catalyst for toluene oxidation in the studied series.