2.Mechanism of autoxidation reaction>R+HO2(7-1)RH+ (ChaininitiationDecisive step is chain initiation in three steps.(homolysis of hydrocarbon to form free radical)R+O2ki→R00(7 - 2)Chain propagationk2(7-3)+RROO + RHROOHThe step ofROOH formation is control step in the chain propagation reactionsR+R_→R-R(7 - 4)Chain termination
2. Mechanism of autoxidation reaction Chain initiation Chain propagation Chain termination Decisive step is chain initiation in three steps. (homolysis of hydrocarbon to form free radical ) The step of ROOH formation is control step in the chain propagation reactions
>RO+OH(7-5)ROOH>ROH+R(7-6)RO+RH(7-7)H,O+ROH+RH(7- 8)2ROOH>R00+RO+H20(7-9)ROO>R'O+R"CHQ或酮(7-10)>ROH或R'OH+RRO(或R'O)+RH
3.Terephthalic acid preparation fromp-xyleneMainreactionsCHOCOOHCOOHCH3COOHO2O21/2021/202+2H20K2K3KiK4(7-11)CH3CH3CH3COOHCHOCHO1/20202KsK6CHO
3. Terephthalic acid preparation from p-xylene Main reactions
SidereactionsCH3(7-12)COx+H2O023CH3(7-13)CH3COOH + O2 → COx + H20Catalyst: Co-Mn-Br mixture catalyst(cobalt acetate,manganeseacetatePromoter:tetrabromoethaneSolvent: acetic acid
Side reactions CH3COOH + O2 → COx + H2O (7-13) Catalyst：Co-Mn-Br mixture catalyst (cobalt acetate, manganese acetate) Promoter: tetrabromoethane Solvent: acetic acid
4. Cumene hydroperoxide preparation by cumeneautoxidationH3CH3HC-00-HCH3CH3
4. Cumene hydroperoxide preparation by cumene autoxidation