固体酸SO_4^(2-)/SnO_2催化转化葡萄糖制备乙酰丙酸丁酯

Conversion of Glucose into Butyl Levulinate over Solid Acid SO_4^(2-)/SnO_2 Catalyst

以沉淀-浸渍法合成的SO24-/SnO2固体酸为催化剂,于丁醇体系中催化葡萄糖转化合成乙酰丙酸丁酯。考察了不同反应条件以及催化剂的重复利用性对产物得率的影响,并利用XRD和NH3-TPD对使用前后的催化剂的结构和酸性进行了表征。实验结果表明:当催化剂于500℃焙烧3 h,用量2.5%,反应温度200℃的条件下反应2 h时,乙酰丙酸丁酯的得率最高达33.1%(摩尔得率,下同);回收利用的催化剂经过焙烧后使用催化性能有所下降,由最初的33.1%下降至回用5次后的12.8%。XRD和NH3-TPD分析结果表明,使用后催化剂的晶型结构仍保留,但酸强度和总酸量随重复使用次数增加却逐渐降低。

Solid acid catalysts SO4^2-/SnO2 were prepared by precipitation and impregnation method for conversion of glucose to butyl levulinate in butanol. The effects of different reaction conditions and catalyst reuse on yields of butyl levulinate were also investigated. The surface structure and acidity of the fresh and reused catalysts were characterized by XRD and NH3-TPD. The results indicated that butyl levulinate yield of 33.1% could be obtained under the conditions of the catalyst calcined at 500℃ for 3 h, catalyst dosage 2.5 % , reaction temperature 200 ℃ and reaction time 2 h. And the catalytic performance for the reused catalysts after calcinations decreased from 33.1% to 12.8% after the fifth reuse. XRD and NH3-TPD results showed that crystallization structure of catalyst was preserved well after reuse, but the acid strength and total amounts of acid were decreased slightly with the increase of the number of reuse.