MOF作模板制备多孔Au/Cu_xO催化剂及其CO氧化性能

MOF-templated preparation of porous Au/Cu_xO catalysts with octahedral structures for CO oxidation

采用MOF材料作模板,通过在Cu-BTC材料表面预先负载贵金属Au再热解的方法,成功制备了具有正八面体结构的新型多孔Au/Cu_xO负载型催化剂。通过降低热解环境中的O_2浓度,调节氧化时间,实现了Au/Cu-BTC氧化产物组分的调节,分别制得了Au/Cu_2O、Au/Cu_2O-Cu O、Au/CuO复合催化材料。将其用于CO催化氧化,发现所有Au/Cu_xO催化剂都表现出比Cu-BTC和Au/Cu-BTC更优异的催化性能,其中由于拥有较高的比表面积、Cu_2O含量以及更好的Au的分散性,Au/Cu_2O的CO氧化活性最佳,180℃即能实现CO的完全转化。

More recently, metal-organic frameworks（MOFs）, as a excellent sacrificial template, have been widely used to fabricate a variety of porous metal oxides with special structures and performances. To take full advantage of MOFs in composition regulation, herein a novel method to prepare porous Au/CuxO composites with octahedral structures inherited from MOFs was introduced. Au/Cu-BTC was firstly prepared by the traditional deposition-precipitation method. Subsequently, pyrolysis of Au/Cu-BTC was conducted in 2%（volume fraction） O_2 balanced with helium. By varying the time of heating, Au/Cu_xO composites including Au/Cu_2O, Au/Cu_2O-CuO and Au/CuO were successfully achieved. When tested in CO oxidation, these supported catalysts exhibited much better catalytic performances than Cu-BTC and Au/Cu-BTC due to the more active support of metal oxides. Thus, Au/Cu_2O showed the best catalytic activity since the high surface area, Cu_2O content and better dispersion of Au.