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

Abstract

On‐site ammonia (NH3) decomposition is considered as a potential path to supply CO x‐free hydrogen for fuel cell vehicles. In this article, monometallic catalysts (Fe, Co, Ni, and Mo) and bimetallic catalysts (Fe–Co, Mo–Co, Fe–Ni, and Mo–Ni) were prepared and tested in plasma‐catalytic NH3 decomposition, where 6Fe–4Ni catalyst exhibited the highest activity and synergistic capability with plasma. At 500°C, NH3 were completely decomposed (>99.9% NH3 conversion); the rate of H2 production and the energy consumption of H2 production reached 0.96 mol g−1 h−1 and 0.050 kW h (mol g−1)−1, respectively. The 200 h continuous operation results indicate an excellent durability of 6Fe–4Ni catalyst. The catalysts characterization and plasma diagnosis results indicate that NH3 was pre‐activated by plasma into excited‐state species (NH3, ˙NH2, and ˙NH), and the 6Fe–4Ni catalyst exhibited the highest capability to adsorb excited NH3, ˙NH2, and ˙NH species, which could be the main reason why 6Fe–4Ni catalyst exhibited the highest activity. © 2018 American Institute of Chemical Engineers AIChE J, 65: 691–701, 2019

Spectroscopic and 1O2 Sensitization Characteristics of a Series of Isomeric Re(bpy)(CO)3Cl Complexes Bearing Pendant BODIPY Chromophores

“…31 Similarly, the manner by which the visible light absorber is attached to the metal center is also critical, as a rhenium bipyridine complex in which a BODIPY light absorber is tethered to a Re(bpy)(CO) 3 Cl core via an alkyne linker shows Φ Δ = 0.88. 59 Accordingly molecular topology is an important consideration in the construction of new complexes that support triplet photochemistry.…”

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

“…The optimized Co 0.89 Fe 2.11 O 4 @mSiO 2 pre-catalyst attained 88% conversion of NH 3 at 600°C and a space velocity of 60 000 cm 3 g −1 h −1 , even maintained for 48 h without attenuation. Similarly, Ni-Fe/Al 2 O 3 , 335,336 Ni-Fe alloys 337 and NiCo/Ce 0.6 Zr 0.3 Y 0.1 O 2 solid solutions 338 were found to show higher catalytic performance than the single metal pre-catalyst toward the decomposition of NH 3 .…”

“…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.…”

Plasma-driven catalysis: green ammonia synthesis with intermittent electricity

“…Next to Ru-catalysts, other supported metal catalysts were tested for plasma-catalytic ammonia synthesis (and ammonia decomposition). 131,152,156,157,159,168,276,277,279,280,[287][288][289][290][291][292] In most cases, supported Co, Ni, and Rh catalysts are found to be most active among the tested catalysts. 131,156,159,276,277 Such metals have less ammonia desorption limitations than the classical Fe and Ru catalysts for thermal-catalytic ammonia synthesis.…”