Experimental study on low temperature catalytic combustion of toluene by Pd/La0.8Ce0.2MnO3 supported on MCM-41

Key words:  VOCs  perovskite  noble metal  catalytic combustion  molecular sieve

Abstract:

Pd/La0.8Ce0.2MnO₃/MCM-41 catalyst was prepared by isovolumetric impregnation method using the noble metal modified perovskite as the active component. The catalytic combustion mechanism was investigated using toluene as the model pollutant, in which the influence of calcination temperature and loading capacity on the catalytic reaction was considered. Also, the catalyst was characterized by Brunauer-Emmett-Teller (BET),X-ray diffraction (XRD) and scanning electron microscope (SEM). It is found that the Pd/La0.8Ce0.2MnO₃/MCM-41 possesses an integrated perovskite structure, on which the Pd has been dispersed evenly, and the catalyst performs good activity. The light-off temperature and the complete combustion temperature of toluene is only 20 3 ℃ and 283 ℃ respectively when the loading capacity of La0.8Ce0.2MnO₃ is 20％ under the calcination temperature of 750 ℃. At the same scenario, the complete combustion temperature of toluene is only 235 ℃ after the modification of adding 0.05％ Pd, which is attributed to the significant enhanced catalytic activity of La0.8Ce0.2MnO₃/MCM-41. Also, the active components on the catalyst show good dispersity with even particle size.