Autothermal hydrogen production via oxidative decomposition of ammonia over vacancy-engineered Ru/CeO₂ prepared by NaBH₄ liquid-phase reduction.
4 affiliations
- 1Department of Chemical and Biological Engineering, Korea University 145 Anam-ro Seongbuk-gu Seoul 02841 Republic of Korea [email protected].
- 2Strategic Research Center for Clean Hydrogen Storage and Utilization, Korea Institute of Science and Technology Seoul 02792 Republic of Korea.
- 3School of Energy and Chemical Engineering, University of Ulsan 93 Daehak-ro, Nam-gu Ulsan 44610 Republic of Korea [email protected].
- 4Strategic Research Center for Smart Battery, Korea Basic Science Institute Daejeon 34133 Korea.
Abstract
Ammonia is a promising hydrogen carrier owing to its high volumetric hydrogen density. Oxidative decomposition of ammonia (ODA) enables autothermal hydrogen production by using the heat released from partial ammonia combustion. However, because this heat is supplied by combusting part of the feed, thermal self-sufficiency and hydrogen yield are intrinsically coupled: at NH₃/O₂ = 4 the oxidized fraction caps the attainable H₂ yield at 66.7%. The central catalytic challenge is therefore to maximize decomposition activity at a fixed combustion fraction. Here we activate Ru/CeO₂ by sodium borohydride (NaBH₄)-mediated liquid-phase reduction instead of conventional high-temperature H₂ reduction, thereby decoupling oxygen-vacancy formation from Ru sintering. The liquid-phase-reduced catalyst (LPR) retained a Ru particle size comparable to that of the mildly reduced catalyst (LT) while exhibiting a markedly higher vacancy concentration by XPS and Ce M4,5-edge EELS. N₂-TPD shows that LPR releases nitrogen at the lowest temperature (370 °C versus 430 °C for LT), consistent with weakened Ru-N binding at the rate-limiting recombinative desorption step, and H₂-TPD with CO/H₂ pulse chemisorption indicates enhanced hydrogen spillover to the support. Thermochemical analysis shows that ODA becomes thermally neutral when about 12.7% of the ammonia feed is oxidized (O₂/NH₃ = 0.095). At O₂/NH₃ = 0.25, LPR delivered a 26.4% H₂ yield versus 20.6% for LT, corresponding to 39.6% and 30.9% of the 66.7% theoretical ceiling. A concept-level techno-economic analysis gives a levelized hydrogen cost of $9.6 kg⁻¹-H₂ at the experimental yield, dominated by the ammonia feedstock.
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BibTeX
@article{lee2026autothermal,
title = {{Autothermal hydrogen production via oxidative decomposition of ammonia over vacancy-engineered Ru/CeO₂ prepared by NaBH₄ liquid-phase reduction.}},
author = {Soohang Lee and Seok-Ho Lee and Minseon Park and Tae Hyun Kim and In Hye Kwak and Hyeon Ih Ryu and Na Young Kim and Jin Suk Chung and Byung Jin Lee and Kwan-Young Lee},
journal = {RSC advances},
year = {2026},
month = oct,
doi = {10.1039/d6ra06193a},
url = {https://europepmc.org/article/MED/42835934},
note = {CC BY},
}
RIS
TY - JOUR
TI - Autothermal hydrogen production via oxidative decomposition of ammonia over vacancy-engineered Ru/CeO₂ prepared by NaBH₄ liquid-phase reduction.
AU - Soohang Lee
AU - Seok-Ho Lee
AU - Minseon Park
AU - Tae Hyun Kim
AU - In Hye Kwak
AU - Hyeon Ih Ryu
AU - Na Young Kim
AU - Jin Suk Chung
AU - Byung Jin Lee
AU - Kwan-Young Lee
PY - 2026
DA - 2026/10/05
JO - RSC advances
DO - 10.1039/d6ra06193a
UR - https://europepmc.org/article/MED/42835934
AB - Ammonia is a promising hydrogen carrier owing to its high volumetric hydrogen density. Oxidative decomposition of ammonia (ODA) enables autothermal hydrogen production by using the heat released from partial ammonia combustion. However, because this heat is supplied by combusting part of the feed, thermal self-sufficiency and hydrogen yield are intrinsically coupled: at NH₃/O₂ = 4 the oxidized fraction caps the attainable H₂ yield at 66.7%. The central catalytic challenge is therefore to maximize decomposition activity at a fixed combustion fraction. Here we activate Ru/CeO₂ by sodium borohydride (NaBH₄)-mediated liquid-phase reduction instead of conventional high-temperature H₂ reduction, thereby decoupling oxygen-vacancy formation from Ru sintering. The liquid-phase-reduced catalyst (LPR) retained a Ru particle size comparable to that of the mildly reduced catalyst (LT) while exhibiting a markedly higher vacancy concentration by XPS and Ce M4,5-edge EELS. N₂-TPD shows that LPR releases nitrogen at the lowest temperature (370 °C versus 430 °C for LT), consistent with weakened Ru-N binding at the rate-limiting recombinative desorption step, and H₂-TPD with CO/H₂ pulse chemisorption indicates enhanced hydrogen spillover to the support. Thermochemical analysis shows that ODA becomes thermally neutral when about 12.7% of the ammonia feed is oxidized (O₂/NH₃ = 0.095). At O₂/NH₃ = 0.25, LPR delivered a 26.4% H₂ yield versus 20.6% for LT, corresponding to 39.6% and 30.9% of the 66.7% theoretical ceiling. A concept-level techno-economic analysis gives a levelized hydrogen cost of $9.6 kg⁻¹-H₂ at the experimental yield, dominated by the ammonia feedstock.
SN - 2046-2069
ER -