(560fx) Enhancement of Heterogeneous Silver and Copper Catalysts Stability for Catalytic Ozonation in Water

Catalytic ozonation represents a promising method to degrade and mineralize refractory organic pollutants in water. Heterogeneous catalysts facilitate easy separation from water and thus have attracted increasing interests in the field of advanced water treatment.

However, the stability of metal/metal oxides based catalysts under ozonation in aqueous solutions represents a challenge.¹ On one hand, metallic ion leaching from the solid catalysts can degrade the quality of treated water and shorten the catalyst lifetime. On the other hand, transition metal ions have been demonstrated as active homogeneous catalysts for catalytic ozonation. The leaching of these ions from their metal or metal oxide counterparts in heterogeneous catalytic ozonation studies will likely to cause questions and controversies in determining the reaction rate expression and mechanisms.

Two strategies to synthesize stable heterogeneous silver- and copper-based catalysts will be discussed in this talk, namely 1) to coat the catalysts with a thin, anti-leaching protecting layer using atomic layer deposition (ALD), and 2) to doped the active sites in the oxide spinel structure. The catalyst structure was characterized using X-ray absorption spectroscopy, XRD, TEM, XPS, and BET surface area measurements before and after the catalytic ozonation in water treatment. Both strategies showed improving catalysts stability in terms of preventing leaching while the catalytic performance was maintained or improved. The advantages and disadvantages of both methods will be discussed and compared.

Reference:

1. Enhancement of Copper Catalyst Stability for Catalytic Ozonation in Water Treatment, W. Yang, Z. Lu, B. Vogler, T. Wu, Y. Lei, ACS Applied Materials & Interfaces, 10 (2018) 43323-43326