高分散PtSn/CeO_(2)催化剂对甲烷完全氧化的促进作用

Promoting Effect of Highly Dispersed PtSn/CeO_(2) Catalyst on Complete Oxidation of Methane

负载型金属催化剂在甲烷完全氧化中应用十分广泛,金属颗粒的大小是决定催化剂性能的关键因素。对于贵金属催化剂,较高的分散性有利于提高催化活性和降低催化剂成本。针对这一问题,以CeO_(2)作为载体、Sn为助剂,在惰性气氛下实现Pt的分散。对制取的催化剂样品进行表征,以分析PtSn/CeO_(2)处理前后的物理结构和电子性质,并研究了其对甲烷完全氧化反应的催化作用。结果表明,PtSn/CeO_(2)具有较高的催化反应活性,在450℃的反应温度中甲烷的转化率达到了95%。这主要归因于Sn的加入削弱了Pt原子从团簇中的解离能,增强了Pt和CeO_(2)之间的锚定作用。利用DFT计算,从热力学角度解释了造成Pt分散差异的原因,为研究催化剂活性金属的烧结与分散提供了新思路。

Supported metal catalysts are widely used in the complete oxidation of methane,with metal particle size being a critical factor in determining catalyst performance.For precious metal catalysts,higher dispersion is beneficial for enhancing catalytic activity and reducing catalyst costs.Addressing this issue,we achieved Pt dispersion under an inert atmosphere using CeO_(2) as a support and Sn as a promoter.The prepared catalyst samples were characterized to analyze the physical structure and electronic properties of PtSn/CeO_(2) before and after treatment,and its catalytic effect on the complete oxidation of methane was studied.The results show that PtSn/CeO_(2) exhibits higher catalytic reactivity,achieving a 95%methane conversion at a reaction temperature of 450°C.This is mainly attributed to the addition of Sn,which weakens the dissociation energy of Pt atoms from clusters and enhances the anchoring effect between Pt and CeO_(2).Using DFT calculations,we explain the reasons for the differences in Pt dispersion from a thermodynamic perspective,providing new insights into the study of sintering and dispersion of active metals in catalysts.