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

• Published in: Water science & technology. Water supply Vol. 23; no. 2; pp. 526 - 545
• Main Authors: Sacco, Nicolas Alejandro, Miranda Zoppas, Fernanda, Aghemo, Vanina, Beltrame, Thiago, Marchesini, Fernanda Albana
• Format: Journal Article
• Language: English
• Published: IWA Publishing 01.02.2023
• Subjects: catalytic nitrate removal; pd–in catalysts; pd–in/al2o3; pd–in/sio2; pd–in/tio2 synthesis design
• ISSN: 1606-9749; 1607-0798
• DOI: 10.2166/ws.2023.019

Abstract Catalysts based on Pd/In were prepared through the wet impregnation method using Al2O3, SiO2, and TiO2 as supports. The impact of the synthesis procedure on N2 selectivity was studied. Characterization was performed using X-ray fluorescence and scanning electron microscopy–energy dispersive spectroscopy analysis. The catalytic performance of these materials was evaluated for nitrate removal from water in a batch reactor. The order of better nitrate removal was found to be Al2O3>TiO2>SiO2. The selectivity towards N2 was also impacted by the support used, with Al2O3-based catalysts being the most selective and TiO2-based the least due to strong metal–support interaction. The synthesis stages also impacted nitrate removal efficiency and selectivity, with the highest N2 selectivity (94.4% at 90% nitrate conversion) found in catalysts where In was added after Pd and underwent intermediate calcination, reduction and final reduction stages.