摘要
复相金属催化剂中的载体效应研究具有重要意义。我们以结构不同的氧化铁载体吸附"非保护型"Pt金属纳米簇制备了具有相同Pt纳米簇的Pt/Fe_3O_4、Pt/γ-Fe_2O_3和Pt/α-Fe_2O_3催化剂,考察了其在无溶剂条件下(本体条件)催化邻氯硝基苯(o-CNB)选择性氢化反应的性能,发现三种铂/氧化铁催化剂的催化选择性远高于商购铂/碳催化剂,Pt/γ-Fe_2O_3和Pt/α-Fe_2O_3的催化选择性明显高于Pt/Fe_3O_4,而Pt/Fe_3O_4的催化活性较Pt/α-Fe_2O_3高50%。铂/氧化铁对不同卤代硝基苯的本体选择性氢化反应表现出优良的催化性能,相应卤代苯胺产物的选择性均可达到99%以上。考察了温度、氢气压力对Pt/Fe_3O_4催化o-CNB本体氢化性能的影响。本工作为理解氧化铁负载金属纳米簇催化剂的特殊催化性质,进而发展高效金属纳米簇基催化体系提供了新的基础。
It is of significance to investigate the support effect in heterogeneous metal catalysts. Pt/Fe2O4, Pt/ y-Fe2O3, and Pt/a-Fe2O3 nanocomposites with the same Pt nanoclusters were prepared by adsorbing Pt colloidal particles stabilized with simple ions and solvent molecules on different iron oxide supports. The catalytic performances over the as-prepared catalysts for the selective hydrogenation of o-chloronitrobenzene （o-CNB） in the absence of solvent were evaluated. It was found that the catalytic activity and selectivity over the prepared iron oxide-supported Pt nanocluster catalysts were higher than those of a commercial Pt/C catalyst. The selectivity towards o-chloroaniline over Pt/y-Fe2O3 or Pt/α-Fe2O3 was higher than that over Pt/Fe2O4, while the catalytic activity over Pt/Fe2O4, was 50% higher than that over Pt/α-Fe2O3. The Pt/iron oxide catalysts also exhibited excellent catalytic properties for the solvent-free selective hydrogenation of other tested halonitrobenzenes, with the selectivity to corresponding haloanilines being 〉 99%. In addition, the influences of temperature and hydrogen pressure on the solvent-free selective hydrogenation of o-CNB over Pt/Fe2O4 were studied. This work is helpful in understanding the superior properties of iron oxide-supported metal nanocluster catalysts and provides a foundation for further developing highly efficient catalytic systems based on metal nanoclusters.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2017年第5期984-992,共9页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(21573010)
科技部国家重点研发计划项目(2016YFE0118700)
北京交通大学人才基金(2015RC070)资助~~
关键词
铂
金属纳米簇
氧化铁
卤代硝基苯
卤代苯胺
选择性氢化
Platinum
Metal nanocluster
Iron oxide
Halonitrobenzene
Haloaniline
Selectivehydrogenation
