Aerosol processing of mesoporous silica supported bimetallic catalysts for low temperature acetone oxidation

One step aerosol EISA (evaporation induced self-assembly) process for synthesizing Ce/metal–MSPs (mesoporous silica spherical particles) catalysts was investigated. The catalysts were then applied to the catalytic oxidation of acetone. The TEM images showed that increasing Ce/Al loading resulted in clearer observation of the metal oxide particles on the MSPs surface, but an excessive metal quantity would destroy the mesoporous structure of the MSPs support. Tests on the monometallic Ce–MSPs and bimetallic Ce/Al–, Ce/Mn- and Ce/Cu–MSPs under temperatures of 150–350 °C demonstrated that Ce/Al–MSPs had the best acetone removal at low temperature ranges of less than 200 °C, and it could have ∼80% acetone removal at reaction temperature of 150 °C, space velocity of 15,000 h−1 and acetone inlet concentration of 1000 ppmv. The synergetic effect was observed for bimetallic Ce/Al–MSPs on the acetone removal as compared to the monometallic Ce–MSPs or Al–MSPs catalysts. The Al loading amount, BET specific surface area and the CeO2 particle size played important roles on the low temperature catalytic oxidation of acetone at 150 °C. The acetone removal of both Ce–MSPs(25) (the molar ratio of Si/Ce = 25) and Ce/Al–MSPs(50/50) (the molar ratio of Si/Ce = 50 and Si/Al = 50) exhibited good stability at 250 °C but decayed gradually at 150 °C after 24 h tests.

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► Ce/Al–MSPs achieved ∼80% acetone removal at T = 150 °C.
► Synergetic effect was observed for Ce/Al–MSPs.
► High stability over 24 h on the acetone removal at 250 °C.