Pd/In-based catalysts for nitrate catalytic removal from water: synthesis designs aiming for better N2 selectivity

Abstract

Pollution of surface and groundwater by nitrates is one of the major worldwide environmental problems. Pd/In-based catalysts were prepared by the wet impregnation method using Al2O3, SiO2, and TiO2 as supports. The influence of the synthesis procedure in the search for catalysts with high selectivity to N2 was studied. The materials were characterized by X-ray fluorescence and scanning electron microscopy-EDS analysis and evaluated in the catalytic nitrate removal from water employing a batch reactor. The catalytic performance was influenced by the support used in the synthesis, obtaining the following order of better nitrate removal: Al2O3 > TiO2 > SiO2. Moreover, the selectivity to N2 is affected by the support used, being Al2O3-based catalyst being the most selective to N2 and TiO2-based catalysts the less one due to the strong metal–support interaction. On the other hand, the order of the synthesis stages affects the nitrate removal efficiency and the selectivity, being the catalysts in which In was added after Pd with intermediate calcination and reduction stages and a posterior reduction, the most selective to N2 (94.4% at 90% of nitrate conversion).

Micro and nanoplastics pollution: A review on global concern and its impacts on ecosystems

“…Research has uncovered their presence in a variety of ecosystems, including oceans, rivers, lakes, soil, and even the atmosphere. This indicates that plastic pollution has escalated into a global issue with far-reaching impacts (Kumar et al, 2022;Kumar, Mishra, et al, 2023;Pandey et al, 2023;Sacco et al, 2023). The widespread distribution of MNPs underscores the urgent need for comprehensive studies to understand their long-term effects on both the environment and human health.…”