Characterization of FeCo based catalyst for ammonia decomposition. The effect of potassium oxide

Abstract

FeCo fused catalyst was obtained by fusing iron and cobalt oxides with an addition of calcium, aluminium, and potassium oxides (CaO, Al2O3, K2O). An additional amount of potassium oxide was inserted by wet impregnation. Chemical composition of the prepared catalysts was determined with an aid of the XRF method. On the basis of XRD analysis it was found that cobalt was built into the structure of magnetite and solid solution of CoFe2O4 was formed. An increase in potassium content develops surface area of the reduced form of the catalyst, number of adsorption sites for hydrogen, and the ammonia decomposition rate. The nitriding process of the catalyst slows down the ammonia decomposition.

Review of the Decomposition of Ammonia to Generate Hydrogen

“…For instance, Huang et al 292 showed an increase in ammonia conversion with respect to the monometallic catalysts, a higher TOF, and a great stability in a 72 h test, demonstrating the synergy between the two metals. Lendzion-Bieluńet al 367 modified a Fe catalyst promoted with CaO, Al 2 O 3 , and K 2 O with cobalt, and obtained a higher conversion with respect to the monometallic catalyst. They also tested a catalyst with a Fe−Co alloy promoted with CaO, Al 2 O 3 , and K 2 O, 368 and determined that the catalytic activity depends on the nitriding potential of Fe.…”

Recent Advances in Bimetallic Catalysts for Hydrogen Production from Ammonia

“…Lendzion-Bieluńet al [79] studied the role of bimetallic Comodified Fe catalyst and the addition of the promoters including the oxides of calcium (CaO), aluminum (Al 2 O 3 ), and potassium (K 2 O) for ammonia decomposition reaction and found that promoted bimetallic catalysts achieved higher ammonia conversions. They, in a different study, also studied the effect of the same promoters (K 2 O, Al 2 O 3 , and CaO) over the performance of CoÀ Fe alloy.…”

Noble-metal-free nanocatalysts for hydrogen generation from boron- and nitrogen-based hydrides

“…224 The catalytic performances of carbon-supported Cu 0.5 Ni 0.5 /CMK-1 and Cu 0.5 Ni 0.5 /MCNS are comparable in the hydrolysis of NH 3 BH 3 and are 3-fold higher than that of silica-supported Cu 0.5 Ni 0.5 /MCM-48. Yu and coworkers successfully immobilized CuNi NPs on six differently sized SiO 2 spheres (47,97,195,333,391 and 485 nm). 229 The results showed that the catalytic activity of CuNi/SiO 2 increases with the decrease of SiO 2 particle size, due to which the CuNi NPs supported on the smallest SiO 2 (CuNi/47-SiO 2 ) exhibit the highest catalytic activity in the hydrolysis of NH 3 BH 3 at 298 K. However, the stability of CuNi/47-SiO 2 showed obvious degradation after seven cycles.…”

“…Bimetallic catalysts with unique structures may achieve excellent catalytic activity in comparison with their individual monometallic components. To date, a series of bimetallic catalysts, such as Co-Mo, [327][328][329] Fe-Mo, 330 Fe-Co, [331][332][333][334] Fe-Ni [335][336][337] and Co-Ni, 338 have been prepared and employed as catalysts for NH 3 decomposition. For example, Duan et al reported that the bimetallic Co-Mo/MCM-41 pre-catalyst shows a higher activity in the NH 3 decomposition reaction than a monometallic Co/MCM-41 or Mo/MCM-41 pre-catalyst under the same conditions.…”