Selective Hydrogenation Of Carbonyl Substituted Nitrobenzene Over Modified Skeletal Nickel

Through Comparative Studying different catalytic system in the same condition, The Mo modifies skeletal Ni catalyst (QS-Ni) was prepared by quenching technique was screened out, and it was employed for the catalytic hydrogenation of4-nitrobenzaldehyde(PNB),4-nitroacetophenone(PNAP). Effects of factors included solvent, reaction temperature, H2pressure, initial concentration of substrate and amount of catalyst have been investigated. Under the optimal workmanship conditions, the stability of QS-Ni has been tested. The Data Showed The catalyst showed excellent catalytic activity, high selectivity to desired product and stability, had a broad industrial prospect.QS-Ni was proved to be extremely active for the hydrogenation of PNB to4-aminobenzaldehyde(PAB). Under the optimal reaction conditions:c(PNB)=0.22mol/L, m(PNB):m(QS-Ni)=10:1,40℃,0.5MPa H2pressure, the selectivity of PAB was up to98.4%with100%conversion of PNB in methanol solvent. The catalyst keeped excellent activity and selectivity after QS-Ni was recycled for13times.QS-Ni was proved to be extremely active for the hydrogenation of PNAP to4-aminoacetophenone(PAAP). Under the optimal reaction conditions:m(PNAP)=1.0g, m(PNB):m(QS-Ni)=20:1,45℃,0.5MPa H2pressure, when the reaction started110min, the selectivity of PAAP was up to99.7%with100%conversion of PNAP in methanol solvent. After QS-Ni was recycled for4times, convertion of PNAP could keep100%and selectivity of PAAP reached96%in the course of time.QS-Ni was used as the catalyst for the deep hydrogenation of PNAP. The reaction conditions:m(PNAP)=1.0g, m(PNAP):m(QS-Ni)=20:1,45℃,0.5MPa H2pressure. The research findings, the deep hydrogenation end-product are4-aminostyrene and4-aminoethylbenzene.