Mössbauer spectra of unreduced catalysts for ammonia synthesis obtained in plasma

New palladium catalysts prepared by glow discharge plasma for the selective hydrogenation of acetylene

“…Connecting the plasma technique with catalysis leads to a new application field: preparation and amelioration of catalysts under the non-equilibrium state [1][2][3][4][5][6]. Vissokov and coworkers [5] prepared the catalyst of ammonia synthesis with higher dispersion at a higher surface area using arc low temperature plasma. Recently, Dalai et al [6] reported that Fe/Co catalysts prepared had an uniformity via plasma treatment.…”

High chemical activity and passivation of ultradispersed particles synthesized under the conditions of electric-arc low-temperature plasma

“…The plasmachemicaUy synthesized and/or regenerated catalysts of the CA-1 type for ammonia synthesis show a catalytic activity that is higher by 15%-25% than that of their conventional analogues; furthermore, their reduction is three to five times faster [9,13,[15][16][17][20][21][22]. Regardless of the reduction method (isothermal or stepwise), they show an extremely high chemical activity (pyrophoric properties) on contact with air.…”

“…These are catalysts for steam conversion (reforming) of natural gas [9,16,18], for low-temperature steam conversion of carbon oxide [9,16,17,19,20] as well as for ammonia synthesis [9,13,[15][16][17][20][21][22].…”

“…The synthesized UDP were characterized by their specific surface using the method of KlyachkoGurvich [26]; their particle size was determined by electron microscopy, their phase and structural composition was studied by X-ray diffraction (Mfssbauer spectroscopy [21,22]) as well as by derivatographic and elemental analyses. Reduction and activation of catalysts were studied by the flow method.…”

Structure and Surface Chemistry of Industrial Ammonia Synthesis Catalysts

“…For an industrial catalyst, energy dispersive X-ray analysis, X-ray powder diffraction, optical microscopy and Mossbauer spectroscopy show that part of the Al and Ca atoms are dissolved in the magnetite lattice [15,27,28,[38][39][40][41][42][43]. The lattice constant of the magnetite phase of an industrial catalyst is 8.377 kX [15].…”