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为了研究粘土的性质对其负载的金催化剂在CO常温氧化反应中的催化活性的影响,将金溶胶分别负载到类水滑石(LDHs)和经过壳聚糖改性的蒙脱石(CS-MMT)表面,得到纳米金颗粒呈高度分散状态的金催化剂样品.通过XRD、XRF、TEM、XPS等手段表征了金催化剂样品的物相、金的含量、金颗粒的粒径分布及金的存在价态,测试了催化剂样品对CO的常温转化率.结果表明:Au0是粘土负载的金催化剂对CO常温氧化反应的主要活性物种,碱性载体LDHs负载的金催化剂样品1.83%Au/Mg Al-CO32--LDHs表面只检测到Au0,金颗粒的平均粒径为2.6 nm,对CO的常温转化率能够达到100%,而酸性载体CS-MMT负载的金催化剂样品1.71%Au/CS-MMT表面同时存在氧化态和金属态的金,且Auδ+/Au0=1.1,金颗粒的平均粒径为2.1 nm,对CO的常温转化率仅为25%.
In order to study the effect of clay properties on the catalytic activity of the supported gold catalysts in CO oxidation at normal temperature, gold sols were loaded onto hydrotalcite-like (LDHs) and chitosan-modified montmorillonite (CS-MMT ) Gold nanocrystals were obtained, and the gold catalyst samples with highly dispersed gold nanoparticles were obtained.The phase and the content of gold, the particle size distribution of gold particles and the existence of gold were characterized by means of XRD, XRD, XRD and XPS. The results showed that Au0 was the main active species for the oxidation of CO at room temperature, and the Au catalyst supported on alkaline carrier LDHs was 1.83% Au / Mg Al-CO32 - only Au0 was detected on the surface of LDHs, the average particle size of gold particles was 2.6 nm, the conversion of CO to normal temperature was 100%, and the surface of the gold catalyst sample 1.71% Au / CS-MMT loaded with CS-MMT Gold exists in the oxidation state and the metal state, and the Au? + / AuO = 1.1, the average particle diameter of the gold particles is 2.1 nm, and the conversion to CO at room temperature is only 25%.