Dimerization of tert-butylmercaptan over the surface of Aerosil (R) impregnated with copper and manganese

Abstract

A ceramic powder of destructive adsorbent was synthesized by impregnating copper and manganese on the surface of silica aerosil(R). In-situ FTIR measurements on pulses of malodorant tert-butylmercaptan injected over the powder showed that tert-butylmercaptan dimerized into di-tert-butyldisulfide on the surface of the adsorbent in an ambient condition. GC/MS measurement on the gas over the adsorbent showed no tert-butylmercaptan remaining, and showed only the dimerization product of di-tert-butyldisulfide. Most of the dimerization product, di-tert-butyldisulfide, remained on the surface of the adsorbent as physisorbed condense, and apparently lowered the destruction efficiency by blocking the surface from the access by tert-butylmercaptan. Upon being heated above 100 degrees C, it was observed that the physisorbed di-tert-butyldisulfide dissociated back into tert-butylmercaptan. Tert-butylmercaptan physisorbed on the activated carbon, thereby no dimerization was occurring on the surface of the activated carbon. In an argon environment, the dimerization reaction was practically not occurring even on the surface of the adsorbent, indicating the free oxygen in air was also participating in the dimerization reaction. Water was identified as a by-product of the dimerization reaction. Possible reactions on the surface of the adsorbent were proposed.