2%Pt/10%MoO_3-ZrO_2催化乙二醇水相加氢脱氧反应的动力学研究

2%Pt/10%MoO_3-ZrO_2 catalyzed aqueous phase hydrodeoxygenation of ethylene glycol:the reaction kinetics

采用等体积浸渍法制备了2%Pt/10%MoO_3-ZrO_2双功能固体催化剂,通过XRD、BET、CO化学吸附、NH3-TPD等手段对催化剂组成、结构和性质进行了表征,并以乙二醇为模型分子研究了2%Pt/10%MoO_3-ZrO_2催化下多元醇水相加氢脱氧过程中的反应动力学特性。结果表明,2%Pt/10%MoO_3-ZrO_2对乙二醇的水相加氢脱氧(HDO)反应具有较好的催化活性和选择性,乙二醇水相HDO反应对乙二醇服从一级反应动力学规律,反应活化能为17.2 k J/mol,与其竞争的重整反应的活化能为111.4 k J/mol。较低的反应温度更有利于提高乙二醇水相HDO的选择性,适宜的反应条件为210℃,5.5 MPa H2,催化剂用量为乙二醇的10%。在此条件下,乙二醇转化率12.5%,HDO产物选择性96.1%。

A bifunctional 2% Pt/10% MoO3-ZrO2 catalyst was prepared by incipient-wetness impregnation method and characterized by XRD,BET,CO-chemisorption,and NH3-TPD. The catalytic activity of 2%Pt/10% MoO3-ZrO2 on aqueous phase hydrodeoxygenation of polyols was systematically studied using ethylene glycol as the model compound. The results showed that 2% Pt/10% MoO3-ZrO2 is effective for aqueous phase HDO of ethylene glycol. The HDO reaction rate was found following the 1storder kinetics withrespect to ethylene glycol,and the activation energy of HDO is only 17. 2 k J/mol,which is much lower than that of the reforming reaction（ 111. 4 k J/mol）. Thus the lower reaction temperature,the better selectivity to HDO products. The optimal HDO conditions were found to be a hydrogen pressure of 5. 5 MPa and a reaction temperature around 210 ℃ with a catalyst loading of 10%. Under this condition,ethylene glycol conversion rate is 12. 5%,and HDO selectivity is 96. 1%.