Liquid-phase oxidation of methyl aromatic hydrocarbons is of great scientific, technological, and commercial importance. In this project, liquid-phase oxidation of p -xylene (PX) to terephtalic acid (TA) was studied with a heterogeneous catalyst immobilization of Co 2+ , Mn 2+ nano-particles on bone by osmosis and impregnation methods which was promoted by KBr. Also glacial acid acetic was used as solvent. Purified terephthalic acid (TA) is an important petrochemical product and the main source of polyethylene terephthalate, a major material for textiles and bottles. About 42 million tons of TA was produced in the world. The nano catalyst was prepared from the cobalt (??) nitrate hexahydrate, Co(NO 3 ) 2 .6H 2 O, and manganese(??) nitrate hexahydrate, Mn(NO 3 ) 2 .6 H 2 O, which were immobilized on bone. Different techniques such as: UV-Vis, BET, SEM, ICP and TEM were used for characterization of the catalysts. The catalyst showed excellent activity and selectivity. For the last several years, the kinetics of the reaction network and the process engineering aspects of p -xylene (PX) oxidation have been investigated in details. The oxidation reaction sequence of p- xylene (PX) generates three intermediates, p -tolualdehyde (TALD), p -toluic acid (PT) and 4-carboxy-benzaldehyde (4-CBA). The products were analyzed by GC. The free-radical chain mechanism, as a general framework within which the kinetics features of hydrocarbon oxidation in liquid phase are interpreted, is now generally accepted. The efficacy of the Co-Mn-Br catalyst system is due to the synergistic effect of the coupled catalytic cycles of cobalt, manganese, and bromide ions. Furthermore, reaction time, temperature, oxygen pressure, catalyst concertation and promoter concertation were optimized. The maximum product (TA) yield was over 99%, which was obtained using 0.1 g catalyst Co/Mn ratio=10/1, 0.01 g KBr at 190 ° C and 17 bar. The reusability of the catalyst, was tested in the reaction. The presence of the bone support makes the nano-particles resistant to aggregation and precipitation and also helps preserve their catalytic activity during the 3 cycles.
