近期我们报道了Au/FeOx-羟基磷灰石(HAP,Ca10(PO4)6(OH)2)催化剂应用于CO氧化反应的研究结果,该催化剂不仅具有很高的低温CO氧化活性和反应稳定性,同时也具有很好的高温抗烧结性能,即使600oC焙烧后依然能够维持很好的CO氧化反应活性.为了进一步研究Au/FeOx-HAP催化CO氧化反应中HAP和FeOx的作用,本文对该催化剂进行了更加深入的表征.X射线光电子能谱结果表明,HAP能与Au和FeOx形成强相互作用,进而在高温条件下稳定Au和FeOx纳米粒子.根据原位漫反射红外结果,FeOx则主要通过改变反应路径和中间产物的方式起到促进催化剂CO氧化活性的作用.结合透射电镜,穆斯堡尔谱和原位漫反射红外结果可知,Au/FeOx-HAP催化剂良好的反应稳定性源于其优异的抗碳酸盐累积能力.
A FeO x ‐modified hydroxyapatite (HAP, Ca10(PO4)6(OH)2)‐supported gold catalyst is highly active and stable during CO oxidation at low temperature, and it is also sinter‐resistant to calcination at temperature up to 600 ℃. This work used catalyst characterization and activity tests to investigate the roles of the HAP support and FeOx promoter in CO oxidation. XPS results suggested that a strong interaction between the HAP support and the Au and FeOx nanoparticles gave the sintering resistance. In situ DRIFT studies revealed that the addition of FeOx changed the nature of the reaction mechanism and intermediates to promote catalytic activity. TEM and M ssbauer examination of the spent catalysts in combination with the in situ DRIFT results suggested that the better stability of Au/FeOx ‐HAP originated from its better prevention of carbonate accumulation.