助剂Cu对Ni/γ-Al2O3催化剂低温还原性能影响

制备了一系列铜质量分数不同的CuNi/γ-Al2O3催化剂，进行了TPR和XRD表征并测定了该系列催化剂对苯加氢制环己烷的催化活性。结果表明，助剂Cu的负载量对低温（160 ℃）还原后催化剂的催化活性影响很大，在铜镍原子摩尔比为1∶1时，催化剂具有较高的催化活性和稳定性；添加铜组分可促进镍在载体表面分散，使负载NiO的还原温度降低，催化活性提高。

Effects of Cu promoter on the low temperature reducibility of Ni/γ-Al2O3

A series of CuNi/γ-Al2O3 catalysts with different Cu contents were prepared and evaluated by the gas-phase benzene hydrogenation as a probe reaction. After reduction at 160 ℃, the Cu-promoted CuNi/γ-Al2O3 catalysts exhibited considerably higher activity than Ni/γ-Al2O3 catalysts, and the copper content played an important role in the catalyst reducibility and catalytic activity. The catalyst, CuNi/γ-Al2O3 with copper to nickel atomic ratio 1∶1, exhibited best catalytic activity and stability. XRD(X-ray diffraction) results showed that the addition of copper to the Ni/γ-Al2O3 catalysts significantly improved the dispersion of NiO over γ-Al2O3, the CuNi/γ-Al2O3 with copper to nickel atomic ratio 1∶1 had optimal dispersion, and further addition was accommodated by the decreasing of the dispersion of NiO. TPR(temperature programmed reduction) results suggested the addition of copper promoted the reducibility of supported nickel oxide by enhancing surface segregation of a NiO-like phase, while copper to nickel atomic ratio in excess of 3∶5 had practically no additional promoting effect.