Combining in Situ NEXAFS Spectroscopy and CO2 Methanation Kinetics To Study Pt and Co Nanoparticle Catalysts Reveals Key Insights into the Role of Platinum in Promoted Cobalt Catalysis
Combining in Situ NEXAFS Spectroscopy and CO2 Methanation Kinetics To Study Pt and Co Nanoparticle Catalysts Reveals Key Insights into the Role of Platinum in Promoted Cobalt Catalysis
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DOI：
10.1021/ja505286j
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发表时间：
2014-07-16
影响因子：
15
通讯作者：
Somorjai, Gabor A.
中科院分区：
文献类型：
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作者：
Beaumont, Simon K.;Alayoglu, Selim;Somorjai, Gabor A.
铂和贵金属在促进用于反应如费-托合成的钴氢化催化剂类型中的机械作用是高度有争议的。在这里，我们使用定义良好的monoclonal Pt和Co纳米颗粒（NPs）和CO2甲烷化作为探针反应，以表明在Co纳米颗粒附近沉积的Pt NPs可以提高CO2甲烷化速率，每个Co表面原子高达6倍。原位NEXAFS光谱的这些相同的Pt NP加Co NP系统在氢气中显示，附近的Pt NP的存在下，能够显着提高还原的Co在温度相关的费托合成和CO2甲烷化。Pt在这些反应中的机械作用进行了讨论，根据这些发现。
The mechanistic role of platinum and precious metals in promoting cobalt hydrogenation catalysts of the type used in reactions such as Fischer-Tropsch synthesis is highly debated. Here we use well-defined monometallic Pt and Co nanoparticles (NPs) and CO2 methanation as a probe reaction to show that Pt NPs deposited near Co NPs can enhance the CO2 methanation rate by up to a factor of 6 per Co surface atom. In situ NEXAFS spectroscopy of these same Pt NP plus Co NP systems in hydrogen shows that the presence of nearby Pt NPs is able to significantly enhance reduction of the Co at temperatures relevant to Fischer-Tropsch synthesis and CO2 methanation. The mechanistic role of Pt in these reactions is discussed in light of these findings.