Synthesis of nitrogen doped segmented carbon nanofibers via metal dusting of Ni-Pd alloy.

[Display omitted] • Ni-Pd (5%) single-phase alloy was used as a catalyst for CCVD of C 2 H 4 Cl 2. • Joint catalytic processing of C 2 H 4 Cl 2 and CH 3 CN into N-doped CNF was studied. • By XPS, produced N-CNF material contains 1.4–2.2 wt.% of structural nitrogen. • Obtained N-doped carbon filaments have regular segmental structure. • The produced N-doped CNF is characterized by S BET ∼ 390−450 m2/g, V pore ∼ 0.6 cm3/g. A single-phase micro-disperse Ni-Pd (5 wt.%) alloy prepared by coprecipitation technique was studied as a catalyst precursor for the synthesis of the nanostructured carbon product. Catalytic synthesis of N-doped carbon nanofibers was implemented by the joint decomposition of C 2 H 4 Cl 2 and CH 3 CN vapors in H 2 excess at 600 °C. The in situ kinetic experiments performed in a flow gravimetric setup with McBain balances showed that the carbon deposition process is characterized by an induction period (18−20 min). The intensive metal dusting of the Ni-Pd alloyed precursor in reaction conditions was found to lead to its complete disintegration. The obtained submicron-sized Ni-Pd particles were shown by XRD to have the same composition as the starting Ni-Pd (5%) precursor. The growth of carbon filaments accompanied the rapid disintegration of Ni-Pd alloy. The addition of acetonitrile vapors into the reaction mixture was found to enhance carbon yield from 24 (0%) to 40.5 (5 vol.%) and 50.9 (8 vol.%) grams per 1 g of catalyst for 2 h of reaction. Joint catalytic processing of C 2 H 4 Cl 2 and CH 3 CN was shown to be sufficient for the production of carbon nanofibers doped with nitrogen. According to XPS and EDX data, the average amount of nitrogen within the obtained N-CNF was about 1.8 wt.%. It was revealed by microscopic studies (SEM, TEM) that the produced N-doped carbon filaments are characterized with a rather regular segmental structure similar to that observed for a reference sample of N-free CNF. The synthesized N-CNF samples are characterized by I D /I G ∼ 1.3 (Raman spectroscopy) and high textural parameters (S BET ∼ 390−450 m2/g, V pore ∼ 0.6 cm3/g). [ABSTRACT FROM AUTHOR]