Construction of superhydrophobic layer for enhancing the water-resistant performance of VOCs catalytic combustion

To improve the water-resistance under rich moisture condition of the monolithic Co3O4/NF (Ni-Foam) catalyst for VOCs catalytic combustion, a hydrophobic coating was carefully designed on the monolithic Co3O4/NF catalyst surface. Through the modulation of the thickness of hydrophobic layer with PhTES (phenyltriethoxysilane), we observed that the thickness of hydrophobic layer on these Co3O4/NF-x%Ph catalysts could greatly affect its activity in the wet conditions. More importantly, it is confirmed that the construction of the superhydrophobic surface derived from PhTES hugely inhibited the conformation of hydroxyl groups (OH) on the monolithic Co3O4/NF catalyst, which effectively restrained the adsorption of moisture on monolithic Co3O4/NF catalyst. Thus, the catalytic activity of toluene under wet condition was improved. In addition, this work also provided new ideas and experimental accumulation for future industrial applications of Co-based catalysts. In addition, in-situ DRIFTS results verified that the construction of hydrophobic layer greatly inhibited the adsorption of water molecules on the surface of the Co3O4/NF-25%Ph catalyst.