Cyano-Anion Intercalated Layered Double Hydroxides for Electrocatalytic Degradation of Acetaldehyde in Gas Phase

Layered double hydroxides (LDHs) are identified as potential material in water splitting or oxygen evolution reaction (OER). Since the water splitting potential is minimized when the use of LDH modified electrode, the application of the LDHs has been still challenged in air pollution control but the water splitting potential should be attempted to extended. Anions or cations intercalation has many applications in electrocatalysis and energy harvesting field. In this approach, the present work aimed to investigate a cyano-anion intercalation on NiCo-LDH and its application to degradation of acetaldehyde in gas phase. The NiCo-LDH was prepared using coprecipitation method under a low temperature. The prepared NiCo-LDH was intercalated with cyano-anion using KCN. After surface characterization to confirm the intercalation of cyano-anion, the NiCo-CN-LDH was coated on a 3D metal foam electrode using a 5% Nafion solution. Redox behavior of the prepared NiCo-CN-LDH electrode was observed in 1M KOH solution by cyclic voltammetry (CV) technique. Once identified the water splitting potential window, the NiCo-CN-LDH electrode was examined on the acetaldehyde (AA) reduction/oxidation in the 1M KOH solution. To evaluate the NiCo-CN-LDH electrode effect on AA, the potential truncated CV at various potential regions. After solution-phase CV analysis, the NiCo-CN-LDH electrode was fitted into Nafion membrane divided electrolytic flow through cell for the gas-phase degradation analysis either by anodic or cathodic half-cell. The NiCo-CN-LDH electrode’s redox behavior was analyzed and compared with solution phase redox behavior. Then the NiCo-CN-LDH electrode was applied on the AA degradation either by oxidation or reduction by continuous flow of AA gas. The degradation efficiency was monitored by ex-situ GC-MS. The promoted effect of cyano-anion on widening the water splitting potential window and its usage on gas phase AA degradation will be discussed in detail at the conference. Acknowledgement: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant No.: NRF-2021R1I1A1A01049901) and from the Grant No. NRF-2020R1A6A1A03042742.