杂多酸盐修饰骨架镍催化剂上肉桂醛的选择加氢

Selective Hydrogenation of Cinnamaldehyde over Raney Nickel Catalysts Modified with Salts of Heteropolyacids

研究了杂多酸盐改性RaneyNi催化剂上肉桂醛选择加氢制备肉桂醇的反应,考察了杂多酸盐负载量、反荷阳离子、杂多阴离子对RaneyNi催化剂上肉桂醛加氢活性和选择性的影响,结果表明:随着Cu1.5PMo12O40负载量增加,肉桂醛加氢活性降低而生成肉桂醇的选择性增加,当Cu1.5PMo12O40负载量达到6.3%时,肉桂醇的选择性达到了26.4%,而没有改性的RaneyNi催化剂上肉桂醛加氢生成肉桂醇的选择性为零;在各种不同反荷阳离子的PMo12盐中,只有反荷阳离子为Cu2+的Cu1.5PMo12O40改性RaneyNi催化剂具有最高的选择性,在选定的四种杂多阴离子的铜盐中,Cu2SiMo12O40和Cu2SiW12O40改性RaneyNi催化剂的选择性为零,Cu1.5PW12O40改性RaneyNi催化剂上肉桂醛加氢生成肉桂醇的选择性也比Cu1.5PMo12O40改性RaneyNi的低的多.

In this paper, liquid phase selective hydrogenation of cinnamaldehdye to cinnamyl alcohol on Raney nickel catalyst modified by salts (including alkali metals, alkaline earth metals, and transition metals) of heteropolyacids with Keggin type structure was studied. Effects of loading, competitive cations and heteropolyanions on catalytic activity and selectivity were examined. It has been found that all Raney nickel catalysts modified with salts of heteropolyacids show lower catalytic activity than unmodified Raney nickel catalysts; 12\|molybdophosphates give the best selectivity among the modifiers. As far as the effect of competitive cations on catalytic properties is concerned, transition metals are better than both alkali metals and alkaline earth metals. Among the transition metal salts, Cu salt is superb in performance. A selectivity as high as 26.4% was attained when an amount of 6.3% Cu1.5PMo12O40 was deposited on the Raney nickel catalyst.