Abstract:

Thermo regulated phase-separable Ir nano catalyst was applied to the selective hydrogenation of α, β-unsaturated aldehydes and ketones and its catalytic hydrogenation performance was systematically investigated. Under the optimized reaction conditions, the Ir nano catalyst exhibited high selectivity of C═O bond for α, β-unsaturated aldehydes (>99%), while high selectivity of C═C bond for α, β-unsaturatedketones (>99%). The catalyst can be simply separated and directly reused for 5 times with the selectivity remaining >99%. Furthermore, the results of TEM showed that the particle size of Ir nano catalyst after four cycles was (1.9 ± 0.2) nm, which increased a little compared with the Ir nano catalyst newly prepared. The results of ICP-AES showed that the leaching of Ir in the upper organic phase was below the detection limit (the detection limit is 5 μg/L).

Key words: thermo regulated phase-separable catalysis, Ir nano catalyst, catalytic hydrogenation, α, β-unsaturated aldehydes, α, β-unsaturated ketones

摘要：

将温控相分离Ir纳米催化剂用于α,β-不饱和醛、酮的选择性加氢反应中，系统考察了其催化加氢性能。在优化的反应条件下，Ir纳米催化剂对α,β-不饱和醛的C═O键加氢选择性大于99%，对α,β-不饱和酮的C═C键加氢选择性大于99%。 Ir纳米催化剂经简单分离可直接循环使用5次，选择性均大于99%。TEM表征结果显示反应四次后的Ir纳米催化剂的平均粒径变为(1.9 ± 0.2) nm，比新制备的Ir纳米催化剂的平均粒径（1.3 ± 0.1）nm有所增大。ICP-AES测试结果表明Ir流失低于仪器检测下限（检测下限为5 μg/L）。

关键词: 温控相分离催化, Ir纳米催化剂, 催化加氢, α,β-不饱和醛, α,β-不饱和酮