CsSmP4O12 crystals have been prepared at 300°C in molten polyphosphoric acids containing Cs, Mg, and Sm cations, and their crystal structure has been determined: sp. gr. I $ \bar 4 $ 3d, a = 15.1225(8) Å, Z = 12, CsNdP4O12 structure.
A sustainable reaction of electrocatalytic nitrate conversion in ammonia production (NO3RR) occurring under ambient conditions is currently of prime interest, as well as urgent research due to the real potential replacement of the environmentally unfavorable Haber–Bosch process. Herein, a series of electrocatalysts based on two-component cobalt alloys was synthesized using low-cost non-noble metals Co, Fe, Cr, and also Si. The samples of electrocatalysts were characterized and studied by the following methods: SEM, EDX, XRD (both transmission and reflection), UV–VIS spectroscopy, optical microscopy, linear (and cyclic) voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Beyond that, the determination of electrochemically active surface area was also carried out for all samples of electrocatalysts. Unexpectedly, the sample having an intermetallic compound (IMC) of the composition Co2Si turned out to be the most highly effective. The highest Faradaic efficiency (FE) of 80.8% at E = −0.585 V (RHE) and an ammonia yield rate of 22.3 µmol h−1 cm−2 at E = −0.685 V (RHE) indicate the progressive role of IMC as the main active component of the electrocatalyst. Thus, this study demonstrates the promise and enormous potential of IMC as the main component of highly efficient electrocatalysts for NO3RR. This work can serve primarily as a starting point for future studies of electrocatalytic conversion reactions in the production of ammonia using IMC catalysts containing non-noble metals.
1 December 2013 in Journal of Alloys and Compounds
CO2-assisted gasification of carbon-based waste materials is one of the processes that both utilises waste carbon chemicals and produces CO, which is a highly sought after raw material. In this work, we aimed at finding and clarifying the synergistic effects of simultaneous potassium and Fe, Co, or Ni-driven catalysis. To reveal the behaviour of such systems, a series with different potassium loadings and a fixed second metal loading of 5 wt.% was prepared. The following methods were applied for this purpose: SEM, TEM, EDX, XRD, electron diffraction, and catalytic tests. The most active sample was found to be 3 wt.% K and 5 wt.% Co- or Fe-loaded hydrolysis lignin. The attained CO2 conversion was up to 92%, while the pure lignin sample demonstrated only 62% conversion under the same conditions.