Use of NiO/SiO_2 catalysts for toluene total oxidation:Catalytic reaction at lower temperatures and repeated regeneration

We deposited NiO via atomic layer deposition on mesoporous SiO2 particles with diameters of several hundred micrometers and a mean mesopore size of -14 nm.NiO was deposited within the shell region of mesoporous SiO2 particles with a shell thickness of -11 mm.We annealed the as-prepared NiO/SiO2 at 450 and 600℃,respectively.These two samples were used as catalysts for the uptake of toluene molecules and their oxidative conversion to CO2.The sample annealed at450℃ was generally more reactive in toluene uptake and its subsequent conversion to CO2.When the NiO/SiO2 annealed at 450℃ was exposed to toluene vapor at 160℃ and then heated to 450℃,CO2 was emitted with almost no toluene desorption.We suggest that our catalysts can be used as building blocks for odor removal devices that operate below 200℃.These catalysts can be regularly regenerated at -450℃.