制备方法对Ni-Al_2O_3催化剂乙酰丙酸加氢性能的影响

Effects of preparation methods on catalytic performance of Ni-Al_2O_3 catalysts for hydrogenation of levulinic acid

分别采用浸渍法、沉积-沉淀法和共沉淀法制备了Ni-Al_2O_3催化剂,采用H2-TPR/TPD、XRD、NH3-TPD等对催化剂进行表征,并研究其催化乙酰丙酸加氢性能。结果表明,共沉淀法制备的催化剂中存在强的金属-载体相互作用、活性金属分散度高以及丰富的酸性中心。该催化剂表现出优异的催化乙酰丙酸加氢合成%-戊内酯性能以及高的使用稳定性。在160℃和4 MPa氢气压力反应条件下,乙酰丙酸转化率与%-戊内酯选择性可分别达85.0%和78.0%,催化剂循环使用3次时活性仍基本保持恒定。

Ni-Al2O3 catalysts were prepared by impregnation,deposition-precipitation,co-precipitation respectively,characterized by H2-TPR/TPD,XRD and NH3-TPD techniques and evaluated in liquid-phase hydrogenation of levulinic acid with ethanol as solvent. The results demonstrated that strong metal-support interaction,highly dispersion of Ni species and large amounts of acidic sites were detected in catalyst prepared by co-impregnation method. The catalyst prepared by co-impregnation exhibited superior performance and highly stability in the synthesis of %-valerolactone via levulinic acid hydrogenation. 85. 0% conversion of levulinic acid with 78. 0% selectivity of %-valerolactone had been achieved at160 ℃,4 MPa of H2 pressure using ethanol as solvent. Both conversion of levulinic acid and selectivity of%-valerolactone remained almost constant after reuse of 3 times.