posted on 2021-12-31, 10:03authored byZhisheng Wang, Yingfa Chen, Xiaotong Li, Guangzhi He, Jinzhu Ma, Hong He
In
previous work, we successfully prepared a NiFe-layered double
hydroxide (LDH) with superior activity and stability for catalytic
ozone decomposition, which fundamentally avoids deactivation under
high-humidity conditions. However, the role of the metal elements
(M2+ and M3+) in LDH catalysts is not clear.
Here, LDH materials containing different metals (NiFe, NiAl, NiMn,
CoFe, and MgFe) were prepared by a simple co-precipitation method.
It was found that the LDHs containing Ni2+ exhibited catalytic
performance far superior to that of Co2+ and Mg2+ for ozone elimination, and NiFe-LDH had the best activity and stability
among LDH materials prepared in this study. The NiFe-LDH can maintain
78% catalytic activity within 144 h at room temperature, even under
a relative humidity of 65% and a space velocity of 840 L·g–1·h–1. Physicochemical characterizations
demonstrated that chemical stability in an oxidizing atmosphere and
the synergic role of M2+ and M3+ ions are crucial.
The result of density functional theory calculation showed that the
synergic role of Ni2+ and Fe3+ weakens the interaction
between O and H in the O–H bond, which effectively lowers the
reaction barrier of ozone decomposition compared with MgFe-LDH.