In:
Journal of Materials Chemistry A, Royal Society of Chemistry (RSC), Vol. 11, No. 23 ( 2023), p. 12062-12079
Kurzfassung:
Anthropogenic flue gases consist of NO X /SO 2 /H 2 O, among which H 2 O resistance is often underrated in activating the acidic/redox cycles of NH 3 -assisted catalytic NO X reduction (SCR), SO 2 /H 2 O-induced evolution of ammonium (bi)sulfate (AS/ABS) poisons, or AS/ABS pyrolysis. Herein, TiO 2 -supported nickel vanadates (Ni X V 2 O X +5 ; X = 1–3) were functionalized with SO Z 2− ( Z = 3–4) to simulate the resulting Ni X –S surfaces under a SO 2 -containing wet flue gas, at which mono/bidentate SO Z 2− modifiers transform into Brønsted acidic bonds (B − –H + ) via protonation. Ni 1 –S exhibited the highest efficiency in the recurring acidic cycle, as proved by its highest NO X consumption rate (− r NO X ) among Ni X –S catalysts. This was enabled by the smallest H 2 O binding affinity to the B − –NH 4 + ⋯O L − –M ( n −1)+ intermediates involved in the rate-determining step of the SCR, thus revealing the smallest energy barrier needed for SCR on Ni 1 –S. Moreover, Ni 1 –S provided the largest quantity of labile oxygens and the highest oxygen mobility among Ni X –S catalysts, leading to the highest efficiency in the recurring redox cycle. Notably, the Ni 1 –S surface repelled H 2 O markedly upon the inclusion of promotive Sb 2 O 5 alongwith the improvement of redox cycling efficiency for the resulting Ni 1 –Sb–S. Hence, aside from exhibiting greater − r NO X values or SCR consequences than Ni X –S and a commercial catalyst (V 2 O 5 –WO 3 –S) at low temperatures, Ni 1 –Sb–S also reduced the number of AS/ABS accumulated by evading H 2 O adsorption. H 2 O resistance was also crucial to accelerate desorptive B − –H 2 O⋯SO 2 ⋯H 2 O dissociation on the Ni 1 –Sb–S surface. Ni 1 –Sb–S thus unveiled a higher AS/ABS degradation rate and a smaller energy barrier required for AS/ABS pyrolysis than V 2 O 5 –WO 3 –S. Importantly, Ni 1 –Sb–S significantly enhanced the resistance toward AS/ABS or hydrothermal aging over V 2 O 5 –WO 3 –S and SO Z 2− -modified Mn 1 V 2 O 6 (or Cu 3 V 2 O 8 ) on Sb-promoted TiO 2 reported previously by our group.
Materialart:
Online-Ressource
ISSN:
2050-7488
,
2050-7496
Sprache:
Englisch
Verlag:
Royal Society of Chemistry (RSC)
Publikationsdatum:
2023
ZDB Id:
2702232-8
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