Nitrogen-free multi-wall carbon nanotubes (MWCNTs) and N-doped bamboo-like carbon nanotubes (BCNTs) were synthesized by using catalytic vapor deposition (CVD) and used as catalyst support materials. Pd, Rh, Ru, and Ir have been deposited onto the nanotubes to achieve metal/nanotube catalysts. The catalytic activity of the samples was fine-tuned by changing the type of support. BCNT supported Pd and Rh (Pd/BCNT, Rh/MWCNT) catalysts were found to be the most active for liquid phase hydrogenation of octadecene amongst these samples. The initial olefin hydrogenation rate of the Pd/BCNT sample was slightly higher than the corresponding MWCNT-supported catalyst. Based on the hydrogenation reaction, the performance of these catalyst had been ranked as follows: Pd/BCNT ≈ Rh/MWCNT > Pd/MWCNT > Rh/BCNT > > Ir/MWCNT > Ru/BCNT > Ir/BCNT > Ru/MWCNT. The structural properties of chemisorbed Pd on MWCNT and N- BCNT were also characterized by means of computational chemical methods in order to shed some light on the nature of metal binding properties of N-doped and undoped surfaces. The calculations shown preference towards the edges of the surfaces which is in good agreement with the experimental findings.

中文翻译：

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通过应用氮掺杂的碳纳米管作为烯烃加氢的催化剂载体来微调催化活性

利用催化气相沉积法（CVD）合成了无氮多壁碳纳米管（MWCNTs）和N掺杂竹类碳纳米管（BCNTs），并将其用作催化剂载体。将Pd，Rh，Ru和Ir沉积到纳米管上以获得金属/纳米管催化剂。样品的催化活性通过改变载体的类型进行了微调。在这些样品中，发现BCNT负载的Pd和Rh（Pd / BCNT，Rh / MWCNT）催化剂对十八烯的液相加氢活性最高。Pd / BCNT样品的初始烯烃氢化速率略高于相应的MWCNT负载的催化剂。基于氢化反应，这些催化剂的性能如下：Pd / BCNT≈Rh / MWCNT> Pd / MWCNT> Rh / BCNT>> Ir / MWCNT> Ru / BCNT> Ir / BCNT> Ru / MWCNT。还通过计算化学方法表征了化学吸附的Pd在MWCNT和N-BCNT上的结构性质，以阐明N掺杂和未掺杂表面的金属结合性质。计算结果表明，其偏向于表面边缘，这与实验结果十分吻合。