Ball-Milled Processed, Selective Fe/<i>h</i>-BN Nanocatalysts for CO<sub>2</sub> Hydrogenation
Denis V. Leybo, Konstantin L. Firestein, Nikolay D. Evdokimenko, Anastasia A. Ryzhova, Viktor S. Baidyshev, Ilya V. Chepkasov, Захар И. Попов, Alexander L. Kustov, Anton S. Konopatsky, Dmitri Golberg, Dmitry V. Shtansky
Abstract
Fe/h-BN nanocatalysts were obtained by a combination of precipitation and high-energy ball-milling (HEBM) techniques. Mechanical treatment at a rate of 300 and 500 rpm induced defects in the h-BN lattice and led to the formation of iron nitride nanoparticles when processing at a higher ball-milling mode. Lewis base centers formed as a result of the interaction of h-BN surface defects with water vapor from ambient air led to an increase in the activity of the Fe/h-BN catalyst in the CO2 hydrogenation. Iron carbides, 2–4 nm in size, formed during the activation stage in the Fe/h-BN nanocomposites after HEBM increased the selectivity toward hydrocarbon formation. Calculations based on the density functional theory showed a significant weakening of the CO bond on the surface of iron carbide and suggested the iron nitride → iron carbide transformation as the most energetically favorable route.