Vapor Phase Amination Reaction of Phenol over Solid Acid Catalysts

Abstract

Vapor phase amination reaction of phenol to aniline was studied by. flow re.actor.met.hod undei atrdospheric pressure; the acidity of catalyst was measured by. n-butylamip.e titr4tiop NPeMpmwrmrmsolid a6ids, Zrb2-WO3 TiO2-Nb20s, and ZrO2-Nb20s, were found and the qcidit and acid strength of theSe acias weredetermined (Table 1). TiO2-SiOz auznd TiP2-ZrO2.-s-h-o-wgd strgnger 6htalyWticactivity than SiO, -A120g. Kinetic studies on TiO2 SiO2 catalyst at 450- C shgwgdtAh-aAt brmhrmen61 reactionrrate was pfoportional to PNM, 6ePpheH 8(at PNH3 O INO-7atm at PhothH O Ol rO 14htm). The activation energy was 23 kcal/mol.The reagtio-n radtek was rgasonably cor.relqsed with the acidity of catalysts, lnthe amination reaction of phenpl derivatives the aminatlon it 12 ele1i'-i-i as concluded 'that the reaction proceeded through the phenol adsorption on the acid-sites 6Tf'catalyst. sites of moderate acid strength were most effective in the reaction. catalysts having highly acidic sites were poisoned by phenol or aniline.