Co-Catalytic Solid-State Reduction Applied to Carbon Nanotube Growth
Co-Catalytic Solid-State Reduction Applied to Carbon Nanotube Growth
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DOI：
10.1021/jp210137u
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发表时间：
2012-01-12
影响因子：
3.7
通讯作者：
Robertson, John
中科院分区：
文献类型：
--
作者：
Bayer, Bernhard C.;Fouquet, Martin;Robertson, John
我们报道了一类用于碳纳米管化学气相沉积的新型助催化剂，其中共成分（钽）作为活性催化剂（铁）的固态还原剂。这种助催化的FeTa体系使得碳纳米管在不需要如H₂或NH₃等还原性气体气氛的情况下就能生长。原位X射线光电子能谱显示，钽（氧化物）通过扩散固态过程从铁（氧化物）中获取氧，这是由于钽对氧的亲和力比铁大得多。我们认为这种基于氧化还原的机制适用于多种金属（氧化物）/催化剂体系，并且通常与多相催化中的合理催化剂设计相关。
We report on a new class of cocatalysts for the chemical vapor deposition of carbon nanotubes, where the cocomponent (Ta) acts as a solid-state reducing agent for the active catalyst (Fe). The cocatalytic FeTa system enables carbon nanotube growth without the need for a reducing gas atmosphere such as H-2 or NH3. In situ X-ray photoelectron spectroscopy reveals that the tantalum (oxide) getters the oxygen from the iron (oxide) by a diffusive solid-state process, driven by the much larger affinity to oxygen of Ta compared to Fe. We suggest that this redox-based mechanism is applicable to a wide range of metal (oxide)/catalyst systems and relevant to rational catalyst design in general heterogeneous catalysis.