Uniformly Dispersed Nicu Catalyst For Reforming

Catalytic reforming is used in the petroleum refining industry to improve the octane number of gasoline, it is one of the most important methods to produce aromatic compounds and by-product hydrogen. The supported Pt catalysts are dominant industrial catalysts, but Pt is rare and expensive, and the sulfur and nitrogen content of raw materials is high limited, the non-noble metal is one research hotspot of the reforming catalyst. We design uniformly dispersed NiCu catalysts and their reforming performance were studied. The specific studies in this paper have carried out as follows:1. The metal elements were uniformly distributed in hydrotalcite with atomics. Using this characteristic of hydrotalcite, we prepared NiCuZnAl-LDH/Al2O3using in situ growth method. Through the topology change, NiCu-ZnAl-LDO/Al2O3catalyst can be obtained. It shows uniformly dispersed structure, and the distribution of NiCu particle is between2-4nm.2. In the hydroconversion of n-heptane reaction. The conversion of n-heptane is34%over NiCu-ZnAl-LDO/Al2O3catalyst, and the selectivity of i-heptane is33%. Its catalytic performance is superior to Pt/ZnAl-LDO/Al2O3catalyst. A higher activity about12%can be obtained with almost the same selectivity. Due to its uniformly dispersed structure, NiCu-ZnAl-LDO/Al2O3catalyst exhibits higher activity isomerization selectivity than NiCu/ZnAl-LDO/Al2O3prepared through a conventional impregnation method.3. Using the regulatability of hydrotalcite metal ions, we prepared hydrotalcite precursors of NiZnAl-LDH/Al2O3, CuZnAl-LDH/Al2O3, NiCuZnAl-LDH/Al2O3, and loaded a small amount of Pt. After calcination and reduction, we get the Pt/Ni-ZnAl-LDO/Al2O3, Pt/Cu-ZnAl-LDO/Al2O3, Pt/NiCu-ZnAl-LDO/Al2O3catalysts. Owing to the synergistic effect of Ni and Cu, comparing the catalytic performance of Pt/NiCu-ZnAl-LDO/Al2O3with Pt/Ni-ZnAl-LDO/Al2O3, the conversions of n-heptane are almost the same. The isomerization selectivity is higher17%and the selectivity of C1-C4is lower7%. The conversion of n-heptane is higher16%over Pt/NiCu-ZnAl-LDO/Al2O3than Pt/Cu-ZnAl-LDO/Al2O3. The selectivity of isomerization and toluene are almost the same, and the selectivity of C1-C4is lower5%.4. We prepared Pt/NiCu-ZnAl-LDO/Al2O3catalysts with different Cu/Ni molar ratios hydrotalcite precursors. With the increase of Cu/Ni ratio, the binding energy of Cu increased constantly, and the binding energy of Ni decreases first and then increases. The electronic structures of Ni Cu have been modified. With the ratio of Cu/Ni increasing from0.61to3.17, the catalytic activity of n-heptane reforming reaction has been improved greatly, which increases from40%to85%. The selectivity of toluene increases from5%to17%.