磷酸盐稳定钨锆复合氧化物载铂催化剂催化甘油氢解反应

Hydrogenolysis of glycerol over phosphated tungsten-zirconium mixed oxides catalyst with supported platinum

用分步浸渍-焙烧法制备了不同含量磷酸盐稳定的钨锆复合氧化物载铂催化剂(Pt/phosphated WO3/ZrO_2)。采用NH3程序升温脱附(NH3-TPD)、X线衍射(XRD)、N2物理吸附-脱附、H2程序升温还原(H2-TPR)和H2脉冲吸附等技术对催化剂进行了表征。用固定床反应器考察了催化剂催化甘油加氢制1,3丙二醇的反应性能。结果表明,随着PO_4^(3-)含量增加,Pt/phosphate WO3/ZrO_2催化剂比表面积呈先增大后减小的趋势,PO_4^(3-)质量分数0.8%的Pt/0.8phosphated WO3/ZrO_2催化剂比表面积达到最大值108 m2/g。适量引入PO_4^(3-)可增大催化剂总酸量,增强催化剂金属还原性,提高了催化剂H2吸附量,Pt/0.8phosphated WO3/ZrO_2催化剂H2吸附量达到最大值110.7μmol/g。Pt/0.8phosphated WO3/ZrO_2催化剂水热处理和反应前后比表面积基本没有变化,反应前后催化剂H2吸附量基本不变,Pt/phosphate WO3/ZrO_2催化甘油加氢稳定性较Pt/WO3/ZrO_2催化剂显著提高。

A series of Pt/phosphated WO 3/ZrO 2 catalysts with different PO 3-4 contents were prepared via the method of stepwise impregnation-calcinations.The physico-chemical properties of the catalysts were characterized by various techniques such as NH 3 temperature programmed desorption(NH 3-TPD),X-ray diffraction(XRD),N 2 physical adsorption-desorption(BET),H 2 temperature programmed reduction(H 2-TPR)and H 2 pulse adsorption,and the hydrothermal stability of WO 3/ZrO 2,phosphated WO 3/ZrO 2 were also investigated.The performance of glycerol hydrogenation to 1,3-propanediol over the prepared catalysts was studied in a fixed-bed continuous-flow reactor.Results showed that the BET surface area of the catalyst increased with phosphate content increasing and reached 108 m 2/g when phosphate content was about 0.8%.Furthermore,the acidity of the samples,the platinum metallicity on the catalyst were enhanced and the catalyst H 2 adsorption improved with H 2 adsorption of 110.7μmol/g at 0.8%phosphate content.The BET surface area and the H 2 uptakes remained unchange with the addition of phosphate after the reaction.The activity of Pt/phosphated WO 3/ZrO 2 was much stable than that of Pt/WO 3/ZrO 2 for the glycerol hydrogenation.