Salt-templated synthesis of Ce/Al catalysts supported on mesoporous silica for acetone oxidation

Abstract

A series of bimetallic Ce/Al catalysts supported on mesoporous silica catalysts were prepared through fast salt-templated aerosol process in this study. The source of sodium silicate precursor was from the alkali-extraction of the opto-electronic industrial waste. The inorganic salt formed during the silicate acidification process was served as an effective and low-cost template, which could be simply removed by water washing at room temperature. The Ce/Al-SiO2 catalysts were fabricated under various aerosol-spraying temperatures, and the temperature effects on the structural and surface properties were investigated by XRD, nitrogen physisorption measurement, SEM/TEM, ICP-MS, 27Al MAS-NMR, UV–vis spectra, H2-TPR and NH3-TPD analyses. The catalytic behavior was further evaluated in terms of acetone oxidation. The results revealed that the catalytic oxidation of acetone is mainly governed by the surface redox property, along with the acidity of the catalysts. The Ce/Al-SiO2-300, with high surface acidity and strong surface reducibility, appeared to have the best acetone catalytic performance at temperatures of 100–300°C and its T90 was at 165°C under acetone inlet concentration of 1000ppmv and GHSV of 15,000h−1. Furthermore, compared with literature data which catalysts were prepared using commercial silicon source and traditional organic surfactant templates, Ce/Al-SiO2-300 showed a comparable catalytic performance, indicating the great potential application of Ce/Al-SiO2 catalysts for the catalytic oxidation of acetone.