丙烷脱氢用高稳定性Pt基催化剂研究进展

Advances in high stable Pt based catalysts for propane dehydrogenation

丙烯作为重要的有机化工原料,国内外对其需求量持续增长,造成供不应求。丙烷脱氢(PDH)工艺是以丙烷为原料定向生产丙烯的技术,具有原料来源广泛、丙烯选择性高、产物简单易分离等优势,备受人们关注。本文主要阐述了近十年PDH反应中高稳定Pt基催化剂结构调控和工艺方面的研究进展。总结发现,Pt基催化剂具有最高的反应活性和丙烯选择性,然而,Pt基催化剂在反应中易积炭失活,且在高温下容易烧结团聚,造成稳定性下降。为提高Pt基催化剂的稳定性,研究者主要从催化剂结构设计和操作工艺条件优化两个角度出发。在Pt活性中心的调控方面:(1)调节Pt位点的结构特性,如分散度、粒径尺寸等;(2)加入金属助剂,如Sn、Cu、Ga、Zn等;(3)调控载体的酸性、比表面积、孔结构、金属-载体的相互作用等,能有效改善Pt基催化剂的抗烧结稳定性与抗积炭性能。在操作工艺条件优化方面,通过向丙烷原料中引入CO_(2)、H_(2)、水蒸气或者其他烷烃可增强Pt基催化剂的抗积炭稳定性、提高丙烯的收率。最后,文章指出有效耦合Pt基催化剂结构与操作条件是进一步提高PDH反应中Pt基催化剂稳定性和丙烯收率的关键。

Propene is an important organic chemical,and its demand has been increasing all over the world recently,resulting in a short supply.Propane dehydrogenation(PDH)is an on-purpose propene production process using propane as the raw material.PDH has attracted much attention due to the advantages of abundant raw materials,high propene selectivity,easy separation of products,etc.The review mainly describes the research progress of structure regulation of high stable Pt based catalysts and processes for PDH in the last ten years.It is concluded that the Pt based catalysts showed the highest activity and propene selectivity.However,Pt based catalysts are easier to deactivate by coking and tend to sinter at high temperature,leading to catalyst stability decease.In order to improve the stability of Pt based catalysts,researches are mainly focused on the design of catalyst structure and the optimization of process conditions.In the regulation of Pt active site,methods of(1)modifying the structure properties of Pt sites,such as dispersion,particle size;(2)introducing metal promoter,such as Sn,Cu,Ga,Zn;(3)regulating the properties of support,such as its acidity,surface area,porous structure,and metal-support interaction,could be adopted to improve the anti-sintering and anti-coking properties of Pt based catalyst.In process optimization,co-feeding CO_(2),H_(2),steam or other alkanes with propane,could greatly improve the anti-coking stability of Pt based catalyst and propene yield.Lastly,it is pointed out that effective coupling of the structure of Pt based catalyst and process condition is the key for improving the catalyst stability and propene yield in the future.