Oxidation of kerosene components in a soil matrix by a dielectric barrier discharge reactor

International audienc

Silver nanocluster catalytic microreactors for water purification

A new method for the elaboration of a novel type of catalytic microsystem with a high specific area catalyst is developed. A silver nanocluster catalytic microreactor was elaborated by doping a soda-lime glass with a silver salt. By applying a high power laser beam to the glass, silver nanoclusters are obtained at one of the surfaces which were characterized by BET measurements and AFM. A microfluidic chip was obtained by sealing the silver coated glass with a NOA 81 microchannel. The catalytic activity of the silver nanoclusters was then tested for the efficiency of water purification by using catalytic ozonation to oxidize an organic pollutant. The silver nanoclusters were found to be very stable in the microreactor and efficiently oxidized the pollutant, in spite of the very short residence times in the microchannel. This opens the way to study catalytic reactions in microchannels without the need of introducing the catalyst as a powder or manufacturing complex packed bed microreactors

Catalytic microreactor with immobilised silver nanocluster for organic pollutant removal from water

The use of microchannels for catalytic reactions represents a considerable experimental opportunity, because of the high surface area to volume ratio these devices typically have. However, incorporating catalysts into microfluidic devices has proven technically challenging. We report the development of a new type of microfluidic device that has a catalytically active metal surface with a large active area built into one of the walls that constitute the microchannel. We test the catalytical activity on an important chemical reaction for drinking water purification: the catalytic ozonation of a typical organic pollutant that is otherwise difficult to remove from the water. pCBA was chosen as model pollutant since it is known to have slow reaction rates with molecular ozone and hence to pose problems in water purification. We find that the catalytic microreactor increases the overall reaction rate by a factor 350 compared to the bulk reaction, owing to both the catalytic activity and the confinement, and is thus highly efficient even for very short residence times

Catkin liked nano-Co3O4 catalyst built-in organic microreactor by PEMOCVD method for trace CO oxidation at room temperature

In this paper, tricobalt tetraoxide (Co3O4) catalyst was coated on the polydimethylsiloxane microchannel by the plasma-enhanced metal-organic chemical vapor deposition technology. The obtained Co3O4 film was characterized by SEM, XRD, XPS, and TEM, and the results show that the as-deposited Co3O4 film was initially composed of many cauliflowers-shaped microclusters. Also, the microcauliflower was transformed from an amorphous phase to a crystal phase when the Co3O4 film was treated by Ar and O2 plasma for more than 20 min, and the crystal lattice line occurred on the surface of nano-sized-Co3O4 particles. Meanwhile, the interface of Co3O4 particles with diameter between 3 and 12 nm became obvious and some nano-catkin structures were also formed on the Co3O4 film. The ratio of Co3+/Co2+ in the spinel-type Co3O4 was nearly 2, and the nano-particles predominantly expose their {311}, {111}, and {220} planes. These morphologies and structure characteristics were found to be ideal for increasing the catalytic activity efficiency of Co3O4 for CO oxidation, and the catalytic stability of Co3O4 coated on the organic microreactor lasted nearly 85 h for trace CO oxidation at room temperature