Platinum Nanoparticles Supported on Hierarchically Porous Aluminosilicate Nanospheres for Low-Temperature Catalytic Combustion of Volatile Organic Compounds

The hierarchically porous silica (NKM-5) and aluminosilicate (Al-NKM-5) supported platinum nanoparticles catalysts were prepared and investigated for the catalytic combustion of toluene and ethanol. The Pt/NKM-5 and Pt/Al-NISI-5 catalysts displayed the submicrometer spherical morphology and the hierarchical pore structure, and the Pt nanoparticles were uniformly distributed. The Pt/NKM-5 and Pt/Al-NKM-5 showed excellent low-temperature catalytic activity and CO2 selectivity, and the hierarchical pores were beneficial to the catalytic combustion of toluene. With the increase of Al content, the catalytic activity of Pt/Al-NKM-5 increased gradually; the Pt/Al-NKM-5-5 catalyst with Si/Al = 5 showed the most excellent catalytic activity with 90% toluene conversion at 146 degrees C and 90% ethanol conversion at 138 degrees C. The NMR and NH3-TPD showed that the incorporation of Al could increase the acidity of support, which could promote the distribution of Pt and the adsorption of toluene as characterized by UV-vis, TEM, CO pulse chernisorption, and FTIR. The excellent catalytic activity of Pt/Al-NKM-5-5 could be ascribed to the hierarchically porous structure, more acidic sites, and higher Pt dispersity.