丙烯环氧化制环氧丙烷Fe-Al-P-O催化剂的研究

用溶胶-凝胶法制得了Fe-Al-P-O催化剂，采用IR、XRD、TEM、BET、TPR和微反等技术研究了催化剂的物化性质和反应性能。实验结果表明，Fe1/2-Al1/2-PO4由10 nm左右 FePO4和AlPO4微晶组合而成，其晶格氧的活泼性大于单纯FePO4，AlPO4在Fe1/2-Al1/2-PO4中起到分散FePO4微晶的作用；Fe1/2-Al1/2-PO4的反应性能与原料气组成密切相关，丙烯与O2的选择氧化产物主要是丙烯醛，原料气中加入H2后，反应产物以环氧丙烷为主，同时还有部分丙烯醛，原料气中引入水蒸气后，可进一步增加环氧丙烷的选择性及减少丙烯醛的产率；在0.1 MPa、200 ℃、C3H6/O2/H2/H2O/N2=1∶1∶1∶1∶6（mol比）和空速1 200 h－1条件下，丙烯的转化率为8.9％，环氧丙烷的选择性为81.0％。

Study on Fe-Al-P-O catalyst for propylene epoxidation to propylene oxide

Fe-Al-P-O catalysts were prepared by sol-gel method. The physical and chemical characters and reactivity of the catalysts were studied by using techniques of IR, XRD, TEM, BET, TPR and micro-reactor. The experimental results revealed that Fe1/2Al1/2PO4 catalyst is a uniform compound of 10 nm particles FePO4 and AlPO4, in which FePO4 is highly-dispersed by AlPO4 and the activity of the lattice oxygen is higher than that in the single FePO4. The reactivity of Fe1/2Al1/2PO4 catalyst is obviously related with the feed composition. In case of propylene and oxygen only as the feed, the outcome is mainly acrolein. Addition of H2 into the feed stream leads to propylene oxide with some acrolein. Addition of H2O into the feed stream consisted of C3H6, H2 and O2, can effectively restrict the formation of by-product acrolein and increase the selectivity to propylene oxide. At a condition of 0.1MPa, 200℃, C3H6/O2/H2/H2O/N2(mol)=1:1:1:1:6 and space velocity of 1200 h-1, the propylene conversion of 8.9% and the propylene oxide selectivity of 81% can be obtained.