A review on the recent developments of ruthenium and nickel catalysts for COx-free H2 generation by ammonia decomposition

Catalytic ammonia reforming: alternative routes to net-zero-carbon hydrogen and fuel

“…In more recent work, high-entropy alloys (HEAs) are proposed to enhance activity and stability under elevated temperatures. 33,34 As a large comparison study, Ganley et al 35 [36][37][38] The differences in mechanistic pathways depend on the metal that is used, and the wide range of reaction conditions result in these active metals having clear advantages over one another in particular situations. Ru-based catalysts exhibit high catalytic activity.…”

“…The results from this study corroborate data found in the literature, as Ru has been regarded as the most active metal for thermal reforming of NH 3 and Ni is reported as the best performing among non-noble metal catalysts. 36–38…”

“…The results from this study corroborate data found in the literature, as Ru has been regarded as the most active metal for thermal reforming of NH 3 and Ni is reported as the best performing among non-noble metal catalysts. [36][37][38] The differences in mechanistic pathways depend on the metal that is used, and the wide range of reaction conditions result in these active metals having clear advantages over one another in particular situations. Ru-based catalysts exhibit high catalytic activity.…”

Low Temperature Thermal and Solar Heating Carbon‐Free Hydrogen Production from Ammonia Using Nickel Single Atom Catalysts

“…[ 9 ] Ni is the benchmark and abundant catalyst for NH 3 splitting, [ 10,11 ] exhibiting relatively high activity for NH 3 splitting among non‐noble metal catalysts. [ 6,12 ] Although a series of Ni‐based catalysts, e.g., NiMgAl‐layered double hydroxides, [ 13 ] La and Ce doped Ni catalysts, [ 14 ] Ni/molecular sieves heterostructures, [ 15 ] Ni‐based solid solutions, [ 16 ] have been investigated, the highest H 2 production rate of Ni‐based catalysts is still limited in ≈4 mmol g −1 min −1 at 600 °C. [ 16 ] Therefore, investigating Ni‐based catalysts active for NH 3 splitting at low temperature (300 °C) is the key to realizing industrialized NH 3 splitting.…”

Y-Doped BaCeO3 Perovskite-Supported Ru Catalysts for COx-Free Hydrogen Production from Ammonia: Effect of Strong Metal–Support Interactions

“…The decomposition of NH 3 to produce H 2 (NH 3 ↔ N 2 + 1.5H 2 ) is an endothermic reaction (Δ H 298 K = 46 kJ·mol –1 ), and the thermodynamic equilibrium conversion is higher than 99% under ambient pressure at 400 °C. − Among the various active species, Ru has exhibited promising performance in the NH 3 decomposition. − Based on previous mechanistic studies, the associative desorption of N 2 from the Ru catalyst is the rate-limiting step in the overall catalytic cycle. − It is extensively recognized that an increase in the electron density of the Ru species promotes associative N 2 desorption . Notably, Ru catalysts supported on electron-rich basic metal oxides, such as MgO, CaO, and CeO 2 , exhibited superior activity compared to those supported on acidic materials. − Based on this perspective, the regulation of the interaction of Ru species with electron-rich basic supports and the formation of the interface, which donates electrons from the support to the Ru species, are essential factors required to facilitate N 2 desorption and improving the catalytic performance for NH 3 decomposition …”