Hydrogenolysis of glycerol to obtain 1,2-propanediol on Ce-promoted Ni/SBA-15 catalysts

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• 作者：I. Jim&eacute ; nez-Morales^a ; F. Vila^b ; R. Mariscal^b ; A. Jim&eacute ; nez-Ló ; pez^a ; ^{ajimenezl@uma.es}
• 关键词：Glycerol ; Hydrogenolysis ; SBA-15 ; Acid catalysts ; Metallic nickel ; Ceria
• 刊名：Applied Catalysis B ; Environmental
• 出版年：2012
• 期刊代码：4_09263373
• 类别：ce
• 出版时间：18 May, 2012
• 卷：117-118
• 期：Complete
• 页码：253-259
• 文件大小：943 K

摘要

Metallic Ni (10 wt.%) supported on SBA-15 silica and promoted with cerium loading ranged between 2.5 and 10 wt.%, reduced at 723 K during 1 h, were used as catalysts in the hydrogenolysis of a glycerol aqueous solution (80 wt.%) at 473 K and 2.4 MPa of H₂ pressure. Whereas pure Ni catalyst mainly produces volatile products by CC hydrogenolysis reaction, the promoted cerium catalysts lead to the formation of 1,2-propanediol (1,2-PDO) as majority product. After 8 h of reaction the catalyst with 10 wt.%of Ni and 7.5 wt.%of Ce gives the maximum glycerol conversion and selectivity to 1,2-PDO, with yield of this substance of 24.2%/g of catalyst. The presence of cerium species is essential to produce 1,2-PDO. The effect of cerium oxide is to act as strong acid sites (TPD-NH₃), improve the metallic Ni dispersion (XRD, H₂ chemisorption and XPS) and to make more difficult their reduction (TPR). The stronger acidity suggests that the formation of acetol takes place easier in these catalysts and subsequently this intermediate is reduced by activated hydrogen from the nearby Ni metallic sites.