Synthesis and characterization of Fe–Ni/ɣ-Al2O3 egg-shell catalyst for H2 generation by ammonia decomposition

Impact of nanoparticle size and lattice oxygen on water oxidation on NiFeOxHy

“…One challenge with nanoparticle catalysts is that they often coalesce under reaction conditions [42][43][44] . In addition, the conditions under which OER electrodes operate can cause metal dissolution 45,46 . As a first step to evaluate the stability and resistance towards corrosion and sintering, SEM images were acquired before and after OER at identical locations to directly visualize any change in particle size or positions 47 .…”

Intraparticle Modeling of Non-Uniform Active Phase Distribution Catalyst

“…As is pointed out above, during catalyst preparation, the active phase distribution is strongly influenced by intraparticle mass transfer limitations. Egg-shell catalysts are well obtained by modulating the immersion time of the support in the precursor solution [5], as lower impregnation times prevent the migration of the active phase toward the inner core of the support. Nevertheless, some research groups preserve the advantages of the IWI approach [5,6], leading to easy control of the active phase loading.…”

“…Egg-shell catalysts are well obtained by modulating the immersion time of the support in the precursor solution [5], as lower impregnation times prevent the migration of the active phase toward the inner core of the support. Nevertheless, some research groups preserve the advantages of the IWI approach [5,6], leading to easy control of the active phase loading. Viscosity, active phase solubility in the precursor solution, concentration, impregnation time and temperature are the operating parameters that optimize the final active phase distribution.…”

“…In the catalytic aromatization of methyl cyclopentane an increase in the conversion was observed when the metallic sites are distributed on the external surface of the particle [18]; egg-shell catalysts are also widely used in the hydrogenation of pyrolysis gasoline [19], ammonia decomposition [5], and the purification of automobile exhaust gases [20,21]. Recently, core-shell and core-double-shell catalysts have been compared in terms of amide production in reactors heated under radiofrequencies (RF), demonstrating that the reaction rates are increased by using an intermediate non-magnetic support layer [22].…”

Plasma‐assisted ammonia decomposition over Fe–Ni alloy catalysts for COx‐Free hydrogen

“…Mainly because the metal–nitrogen binding energies of Ni and Co are approximately 122 kcal mol −1 and 125 kcal mol −1 , respectively, lower than that of Ru–N, whereas the metal–nitrogen binding energies of Fe and Mo are approximately 148 kcal mol −1 and 154 kcal mol −1 , respectively, higher than that of Ru–N. Thus, bimetallic catalysts such as Fe–Ni, Fe–Co, and Mo–Co have been studied in NH 3 decomposition, based on the idea that the combination between a metal with low metal–nitrogen binding energy (<134 kcal mol −1 ), and another metal with high metal–nitrogen binding energy (>134 kcal mol −1 ) may produce a bimetallic catalysts with moderate metal–nitrogen binding energy. This idea may achieve synergistic effects on NH 3 decomposition in particular cases.…”