H_3PW_(12)O_(40)/SiO_2催化氧化甘油制备二羟基丙酮

采用等体积浸渍法制备了PW/SiO2催化剂(PW为H3PW12O40),在固定床反应器上对甘油选择性氧化制备二羟基丙酮(DHA)的反应进行了研究;采用BET,XRD,FTIR,NH3-TPD,TG等方法对PW/SiO2催化剂进行了表征。实验结果表明,PW的负载量及焙烧温度对PW/SiO2催化剂的酸性及其活性有明显的影响,当PW的负载量(基于SiO2载体的质量)为10%(w)、焙烧温度为350～400℃时制备的PW/SiO2催化剂的酸量和酸强度适宜,对甘油氧化制备DHA的反应具有较高的活性;在反应温度60℃、常压、空气流量20 mL/min、液态空速0.06 h-1、甘油水溶液的含量10%(w)、PW负载量10%(w)的PW/SiO2催化剂1 g的条件下,DHA的收率达到39.1%。

Selective Oxidation of Glycerol to Dihydroxyacetone over H3PW12O40/SiO2 Catalyst

PW/SiO2 catalysts(PW:H3PW12O40) with different PW loadings were prepared at different calcination temperatures and characterized by BET,XRD,FTIR,NH3-TPD and TG.The selective oxidation of glycerol to dihydroxyacetone(DHA) was studied over the catalysts in a fixed bed reactor.The effects of catalyst composition,pretreatment and reaction conditions on the selective oxidation were examined.The results show that the PW loading and calcination temperature have significant influences on the acidity and the catalytic activity of PW/SiO2 catalysts.The catalyst with PW loading of 10%(w)(based on SiO2 support mass) calcined at 350-400 ℃ exhibits the best catalytic performance.For the selective oxidation of glycerol,the yield of DHA is 39.1% under the conditions of 10%(w)PW/SiO2 dosage 1 g,60 ℃,LHSV 0.06 h-1,atmospheric pressure,10%(w) glycerol aqueous solution as the feed and air flowrate 20 mL/min.