Pd@MgAl LDH/2-ThCA: A sustainable, active and recyclable nanocatalyst system for the rapid and efficient catalytic reduction of organic pollutants

Abstract

Catalytic reduction of toxic pollutants such as nitroaromatics and organic dyes found in water/wastewater by heterogeneous nano-structured metallic catalysts is a promising method for wastewater treatment. The need for effective and reusable catalyst systems is recently increasing due to the soaring water pollution. For this purpose, in this study, a newly Pd@MgAl LDH/2-ThCA catalyst system was successfully developed by depositing palladium nanoparticles onto a modified MgAl LDH support, characterized and then used to eliminate these contaminants in the presence of NaBH4. Catalytic applications indicated that Pd@MgAl LDH/2-ThCA catalyst efficiently reduced 2-nitroaniline (2-NA), 4-nitrophenole (4-NP), 4-nitroaniline (4-NA), and 4-nitro-o-phenylenediamine (4-NPDA) with rate constants of 0.011 s−1, 0.0075 s−1, 0.017 s−1, and 0.02 s−1, respectively. Additionally, Pd@MgAl LDH/2-ThCA successfully degraded methyl orange (MO) and rhodamine B (RhB) with rate constants of 0.019 s−1 and 0.015 s−1, respectively. Furthermore, it was found that methylene blue (MB) was immediately degraded by Pd@MgAl LDH/2-ThCA. Reusability tests revealed that Pd@MgAl LDH/2-ThCA maintained its activity/stability after the 5 successive cycles, verifying its practical application potential. This paper reveals that Pd@MgAl LDH/2-ThCA is an effective, sustainable, and alternative catalyst system for the treatment of toxic environmental pollutants.