摘要
糠醛是木制纤维素的水解产物,由于其分子结构中含有多个官能团且官能团的结构异常敏感,糠醛选择性催化加氢可制得2-甲基呋喃、糠醇、四氢糠醇、呋喃、四氢呋喃等一系列高附加值化学品.因此,制备了一种高活性、高选择性(四氢糠醇)、稳定性好及贵金属负载量低的负载型催化剂.采用硼氢化钠液相化学还原法合成了具有不同Pd负载量的Pd/WO3催化剂(0.34％、2.0％和4.5％),考察了 Pd的负载量及反应温度对Pd/WO3催化糠醛选择性加氢的影响,结果表明,最佳反应条件为:2.0％Pd、反应时间为2 h、反应温度为150℃,此时糠醛转化率为99.0％,四氢糠醇选择性达92.2％.低温反应(100℃)时升高Pd负载量有利于提高催化剂性能,高温反应(150℃)时Pd最佳负载量为2.0％.
Abstract
Furfural is a product from hydrolysis of lignocellulose.Because it contains multiple functional groups in its molecular structure and the structure of functional groups is extremely sensitive,a series of high-value chemicals,such as 2-methylfuran,furfuryl alcohol,tetrahydrofurfuryl alcohol,furan and tetrahydrofuran,can be obtained through selective catalytic hydrogenation of furfural.Thereby,a supported catalyst with low noble metal loading,high activity,high selectivity(for tetrahydrofurfuryl alcohol),and excellent stability is prepared.Pd/WO3 catalysts with various Pd contents(0.34 wt％,2.0 wt％and 4.5 wt％)are prepared via NaBH4 liquid phase chemical reduction method,and the effect of Pd content and reaction temperature on the catalytic behaviors of Pd/WO3 for selective hydrogenation of furfural is also investigated.The optimal reaction conditions are determined as follows:the loading amount of Pd is 2.0 wt％,reaction lasts for 2 h,and reaction temperature is 150℃.Under the optimal conditions,the conversion of furfural reaches 99.0％and the selectivity of tetrahydrofurfuryl alcohol reaches 92.2％.The higher Pd loading is beneficial for improving the performance of the catalyst under low temperature reaction(100℃),while the optimal Pd loading is 2.0 wt％under high temperature reaction(150℃).
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