Ozone generation enhanced by silica catalyst in packed-bed DBD reactor

In this paper,three dielectric barrier discharge(DBD)configurations,which were plain DBD with no packing,DBD with packed pure quartz fibers and DBD with packed loaded quartz fibers,were employed to investigate the effect and catalytic mechanism of catalyst materials in a packed-bed ozone generator.From the experimental results,it was clear that the DBD configuration with packed pure fibers and packed loaded fibers promotes ozone generation.For the packed-bed reactor,ozone concentration and ozone yield were enhanced by an increase of electric field in the discharge gap with the packed-bed effect.Meanwhile,the enhancement of ozone concentration and yield for the DBD reactor packed by loaded fibers with silica nanoparticles was due to the catalysis of silica nanoparticles on the fiber surface.The adsorption of silica nanoparticles on the fiber surface can prolong the retention time of active species and enhance surface reactions.

Silica gel catalyzed α-bromination of ketones using N-bromosuccinimide: An easy and rapid method

An easy and rapid method for the α-bromination of ketones using N-bromosuccinimide （NBS） catalyzed by silica gel in methanol under reflux conditions was developed. The expected products were formed in excellent isolated yields within a short period of time （5-20 min）. Major advantages of the present procedure include use of inexpensive and readily available catalyst, exclusion of pre- and post-chemical treatment of catalyst and use of methanol as solvent instead of ethers and chlorinated solvents.

Single molecule electro-catalysis of non-fluorescent molecule

Single molecule catalysis is very powerful in revealing catalytic mechanism at the single molecule level.But fluorescent molecule is always necessary to take part into the catalysis directly in previous research.In order to study the single molecule electro-catalysis of non-fluorescent molecule（SMECNFM） on nanocatalyst, we couple the SMECNFM with a single molecule fluorescence reaction. A certain number of fluorescent molecules will be generated and detected when the SMECNFM happens. Through this method, we can detect the electro-oxidation reaction of one HCOONa molecule. The stability of Pt nanocatalyst supported on active carbon is studied at the single molecule level by this method. This paper also provides a general way to make ultra-sensitive sensor, and to study the SMECNFM for the molecules,such as formic acid, hydrogen, oxygen, etc., on single nanoparticle.

A novel and facile synthesis of 4-arylquinolin-2(1H)-ones under metal-free conditions

A novel and facile synthesis of 4-arylquinolin-2（1H）-ones without metal catalysis has been developed.This reaction involved cyclization/elimination steps and was performed under metal-free conditions using inexpensive reagents such as NaI, selectfluor and KOH.