采用水热合成法制备磷酸铝分子筛AlPO-5,并通过焙烧处理得到AlPO-5分子筛多孔材料,以浸渍法和沉淀法分别制备了Pt负载型AlPO-5催化剂,通过粉末XRD、TEM、氮气吸附-脱附等手段对制备的催化剂进行了对比表征,研究了负载方法对Pt团簇分散度以及粒径尺寸的影响。以Pt/AlPO-5作为催化剂,研究了其对甘油的催化氧化性能,系统考察了Pt负载量、还原方法和反应时间对甘油转化率和产物选择性的影响。实验结果表明,由浸渍法制备的催化剂对甘油的转化率和甘油醛的选择性较高,甘油醛的选择性最高可达到63.46%。甘油醛作为起始反应产物,其高选择性与较大尺寸的Pt纳米团簇有关。
Aluminum phosphate molecular sieve AlPO-5 was synthesized by hydrothermal method,and then calcined to obtain the porous AlPO-5 supporting material. Pt-loaded AlPO-5 catalyst was prepared by impregnation method and precipitation method,separately,and the catalyst was characterized by powder XRD, TEM and nitrogen adsorption-desorption. Effects of loading method on the dispersion of Pt clusters and particle size were examined;meanwhile,the catalytic performance of Pt/ AlPO-5 on glycerol oxidation was studied. Effects of Pt loading,reduction method and reaction time on glycerol conversion and product selectivity were examined in detail. Results show that the catalyst prepared by impregnation method displays a higher conversion and selectivity of glyceraldehyde (up to 63. 46%). Glyceraldehyde as a starting reaction product during glycerol oxidation,its high selectivity is closely related to Pt nanoclusters with larger size.