CuNiAl催化乙酰丙酸转移加氢制备γ-戊内酯的研究

Catalytic transfer hydrogenation of levulinic acid to γ-valerolactone over CuNiAl catalysts

通过共沉淀法成功合成CuNiAl-LDH前体,将其直接还原制备一系列CuNiAl催化剂,并考察其在催化乙酰丙酸转移加氢制备γ-戊内酯的反应性能,研究了活性组分、还原温度、供氢溶剂、反应温度和反应时间对催化性能的影响。结果表明,Cu组分加入后生成CuNi合金,显著提高了催化活性,且当n(Cu)∶n(Ni)∶n(Al)为1∶14∶5、还原温度为500℃时,催化性能最佳。以异丙醇为供氢溶剂,在170℃下反应120 min,乙酰丙酸的转化率和γ-戊内酯的选择性分别达到98.2%和83.1%。

A series of CuNiAl catalysts are prepared through direct reduction of CuNiAl-LDH precursors which are obtained by coprecipitation method, and utilized to catalyze the transfer hydrogenation(CTH) of levulinic acid to produce γ-valerolactone.The effects of active components, reduction temperature, hydrogen donor, reaction temperature and reaction time on the catalytic performance of the catalysts are investigated.The results show that the addition of Cu into the catalyst can lead to generate CuNi alloy, which improve the catalytic activity greatly.CuNiAl catalyst that is made with a molar ratio of 1∶14∶5 between three elements at a reduction temperature of 500℃ exhibits the highest activity in CTH.The selectivity of γ-valerolactone reaches 83.1% and the conversion of levulinic acid reaches 98.2% when the catalyst with the highest activity is used, 2-propanol is used as the hydrogen donor and solvent, and the reaction has performed at 170℃ for 120 min.