炭载体对Pt-C复合物非碱性条件下催化甘油氧化性能的影响

采用等量浸渍法制备了具有相似平均粒径的活性炭（AC）和碳纳米管（CNTs）负载的Pt催化剂，并比较研究了非碱性条件下两种催化剂催化甘油氧化反应的性能。结果表明，炭载体对Pt-C复合物催化甘油氧化反应的活性、选择性和稳定性有重要影响。相对于Pt/CNTs催化剂，Pt/AC催化剂中Pt 4f结合能较低，导致其表面氧的覆盖度相对较高，因而抑制了甘油的吸附，降低了甘油氧化反应的初始活性；Pt/AC催化剂会促进甘油醛进一步氧化成甘油酸以及C₃产物的氧化断键；Pt/AC催化剂失活的主要原因是氧中毒和中间产物的吸附，而Pt/CNTs催化剂的失活主要是由于甘油酸的吸附堵塞Pt表面的活性位造成的。

Effects of carbon support on glycerol oxidation over Pt-C composite catalysts in base-free conditions

Activated carbon (AC) and carbon nanotubes (CNTs) supported Pt catalysts with similar particle sizes prepared by incipient wetness impregnation method were used for study of base-free oxidation of glycerol. The results showed that carbon support of Pt-C composite catalysts had significant impact on reactivity, selectivity, and steady state of glycerol oxidation. Compared to Pt/CNTs catalyst, Pt/AC catalyst had a lower binding energy of Pt 4f leading to a higher oxygen coverage on catalyst surface which reduced glycerol adsorption and initial activity of glycerol oxidation. Pt/AC catalyst further favored oxidation of glyceraldehyde to glyceric acid and C-C bond cleavage of C₃ products. With regards to catalyst deactivation, oxygen poison and adsorption of intermediates were main factors to Pt/AC catalyst while blockage of Pt active sites by adsorption of glyceric acid was a significant contributor to Pt/CNTs catalyst.