Selective Catalytic Oxidation of O-xylene to Phthalic Anhydride over VPO/HZSM-5: An Optimization Study

Journal of Chemical Reactivity and Synthesis

دوره 10، شماره 4، اسفند 2020، صفحه 167-174   

نوع مقاله: Research Article

نویسندگان

Ali Monajemi^* ؛ Vahid Mahdavi

Department of Chemistry, Surface Chemistry and Catalysis Division Faculty of Sciences, Arak University, Arak 38156-8-8349, Iran

چکیده

Selective gas-phase oxidation of o-xylene to phthalic anhydride over VPO/HZSM-5 catalysts was investigated. The catalysts with various P/V ratio were facilely synthesized by impregnation method. The prepared catalysts were characterized by several techniques such as SEM, TPD-NH3, H2-TPR, FT-IR, BET and XRD. The effects of P/V ratio (1.6–2.4), reaction temperature (350–450 ◦C), Ox/O2 ratio (0.15–0.60) and gas hourly space velocity (G.H.S.V) of O2/N2 (600–1200 h^-1) on yield of PA were studied by Box–Behnken design. The influence of independent factors and their quadratic interactions were examined by means of the Analysis of Variance (ANOVA). Present results indicate that P/V ratio has a different effect on the conversion and selectivity of PA. The catalyst with P/V ratio = 2.0, Ox/O2 ratio = 0.37, G.H.S.V of 770 h^-1 and reaction temperature of 370 ◦C produced maximum yield of PA (80.7 %). The analysis revealed that the predicted results agree well with the experimental data (P/V ratio = 2.0, Ox/O2 ratio = 0.38, G.H.S.V of the carrier gas = 900 h^-1 and reaction temperature of 400 ◦C with 74.3% yield).

کلیدواژه‌ها

VPO/HZSM-5 catalyst؛ phthalic anhydride؛ selective oxidation؛ o-xylene