偏硼酸镁修饰的铂钨铝复合氧化物催化甘油氢解

Hydrogenolysis of glycerol catalyzed by magnesium metaborate modified Pt-W-Al composite oxide

采用等体积浸渍法制得Pt/WO_(x)/Al_(2)O_(3)(W/Al)及Pt-xMgB_(2)O_(4)/W/Al催化剂样品。利用X射线衍射(XRD)、NH_(3)程序升温脱附(NH_(3)-TPD)、CO脉冲吸附、H_(2)程序升温还原(H_(2)-TPR)技术对催化剂进行表征。在水热釜中进行水热处理(水相温度200℃),考察催化剂的水热稳定性能,在固定床反应器上通过甘油选择性氢解生成1,3-丙二醇反应考察催化剂的催化活性。结果表明,偏硼酸镁修饰的W/Al载体表面γ-Al_(2)O_(3)晶相并未发生改变,且总酸量增大;偏硼酸镁的引入提高了载体表面Pt的分散度,水热稳定性能得到提升;在H_(2)压力4 MPa、甘油质量分数40%、反应温度160℃条件下,甘油转化率和1,3-丙二醇选择性分别达到60%及49%。

In this paper,Pt/W/Al and Pt-xMgB_(2)O_(4)/W/Al samples were prepared by impregnation of MgB_(2)O_(4) and Pt on the prepared WO_(x)/Al_(2)O_(3)(W/Al)supports.The catalysts were characterized by X-ray diffraction(XRD),NH_(3)-TPD,CO pulse adsorption and H_(2)-TPR.In order to study the stability and activity of the catalyst,the hydrothermal stability of the catalyst was investigated by hydrothermal treatment(water phase temperature 200℃),and the catalytic activity of the catalyst was investigated by selective hydrogenolysis of glycerol to 1,3-propanediol in a fixed bed reactor.The results show that the crystal phase of γ-Al_(2) O_(3) on the surface of the W/Al carrier modified with magnesium metaborate does not change,and the total acid content increases.The H_(2) adsorption performance and the dispersion of Pt on the surface of the support are greatly improved,with excellent hydrothermal stability.Under H_(2) pressure of 4 MPa,glycerol mass fraction of 40%and reaction temperature of 160℃,the conversion of glycerol and selectivity of 1,3-propanediol were 60% and 49%,respectively.