非晶态雷尼镍催化剂低温催化生物油模型化合物加氢的研究

Amorphous Raney Nickel Catalyzed Hydrogenation of Bio-Oil Model Compounds under Relatively Low Temperatures

采用非晶态雷尼镍催化剂,在高压反应釜内对二丙酮醇、糠醛、苯酚和愈创木酚等生物油模型化合物进行低温催化加氢实验,研究了模型化合物催化加氢特性、反应机理以及催化剂性质。实验结果表明:温度是影响此类催化剂活性的最主要因素,温度过高容易导致催化剂晶化而降低催化活性;在反应温度180℃、压力3MPa、反应时间4 h以及催化剂量8%(wt)时,模型化合物的转化率和饱和醇的选择性分别达到100.00%和97.74%以上;在此反应条件催化真实生物油的体系中,饱和醇的收率达到44.00%,p H从4.08升至5.13;通过对模型反应机理的探讨,得出模型主要通过两种加氢方式进行:即不同化合物分别以其O上的孤对电子选择性地与催化剂上的两种活泼态H(弱吸附的Ni-H、游离的原子态氢)进行加氢反应,完成催化加氢过程。

Bio-oil model compounds （diacetone alcohol, furfural, phenol and guaiacol） hydrogenation catalyzed by amorphous Raney nickel was studied in an autoclave under relatively low temperatures. The hydrogenation characteristics, reaction mechanism and catalyst properties were investigated. The results show that high temperature causes catalyst crystallization and reduces catalytic activity. The conversion rate of the model compounds and the selectivity of saturated alcohols are 100.00% and 97.74% respectively under optimal conditions of 180℃, 3 MPa, 4 h and 8%（wt） catalyst. The yield of saturated alcohols reached to 44.00% with bio-oil and the pH changed from 4.08 to 5.13. Two hydrogenation mechanisms were proposed, i.e. compounds with lone pair electrons of O selectively combined with two active H（weak absorption Ni-H, free hydrogen atoms） for hydrogenation reaction.