Hydroisomerization Of N-Heptane Over Molecular Sieve Catalysts Promoted By Ce

The Bifunctional Catalyst NiCe/SAPO-11and Ni-SiW₁₂-Ce/Al-MCM-41wasprepared by substep impregnation method.The catalysts were characterized by using XRD, BET surface area,SEM and IR.The isomerization of n-heptane over NiCe/SAPO-11and Ni-SiW₁₂-Ce/Al-MCM-41catalyst was investigated in a continuous flow fixed-bed reactor under atmospheric pressure. The effect of preparation condition and reaction condition on the catalytic performance were studied.The result showed that the introduce of Ce is beneficial to improve catalyst performance, while increasing the stability of NiCe/SAPO-11and Ni-SiW12-Ce/Al-MCM-41catalyst.NiCe/SAPO-11Catalyst with Ni4%content and w(Ce):w(Ni)=1:1, reductiontemperature500℃, reduction time6h possessed better performance. The bestreactioncondition was reaction temperature300℃and W/F=5gcath/mol. The conversion of n-heptane and the isomerization selectivity to i-heptane could reach18.1%and72.6%, respectively.Ni-SiW12-Ce/Al-MCM-41catalyst with Ni4%content and SiW1220%content, reduction flow rate of H250mL/min and reduction temperature400℃possessed better performance. The best reaction condition was reaction temperature270℃, W/F=15gcath/mol and flow rate of H250mL/min. The conversion of n-heptane and the isomerization selectivity to i-heptane could reach22.3%and65.4%,respectively.