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[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]

Abstract: A series of 1.8wt.% PdAu/γ-Al2O3 catalysts with a mean metal particle size of more than 10nm and different Pd/Au ratios were prepared by impregnation followed by hydrazine reduction and tested in the decomposition of vapour phase formic acid (2.2vol.%, 1bar) with and without added CO to the gas mixture. The catalytic activity was correlated with the bulk (AAS, XRD, EDS/TEM) and surface (XPS) composition of PdAu particles. A novel result was obtained that the surface composition of the particles did not change despite a considerable variation of the Au atomic fraction and it was found to be close to that of the Pd2Au alloy. The activity of the Au/Al2O3 catalyst was negligible compared with that of the Pd/Al2O3 catalyst being a factor of 65 lower per gram of metal at 403K. The surface electronic properties (XPS) and the catalytic activity of the Pd2Au layer calculated per one surface Pd atom (TOF) did not depend on the bulk composition of the metal particles. A lower activity of the Pd2Au layer as compared with the pure Pd layer (2–3 times) was observed, but the activation energies for the Pd and PdAu catalysts were similar (40kJmol−1) and were lower than that for the Au/Al2O3 catalyst (62kJmol−1). Addition of CO led to a considerable inhibition of the reaction for all PdAu catalysts, this being accompanied by an increase in the activation energy to 69kJmol−1. [Copyright &y& Elsevier]