Palladium-copper and palladium-tin catalysts in the liquid phase nitrate hydrogenation in a batch-recycle reactor

• Published in: Applied catalysis. B, Environmental Environmental, 2004-09, Vol.52 (1), p.49-60
• Main Authors: Pintar, Albin, Batista, Jurka, Muševič, Igor
• Format: Article
• Language: English
• Subjects: Atomic force microscopy (AFM); Batch-recycle reactor; Bimetallic catalysts; Catalytic nitrate hydrogenation; Energy dispersive X-ray microanalysis (EDX); Integrated ion-exchange/catalytic denitrification process; Pd-Cu; Pd-Sn; Point of zero charge (pHpzc); Scanning electron microscopy (SEM)
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2004.02.019

Catalytic liquid phase nitrate reduction was investigated at T=298K and atmospheric pressure in an isothermal batch-recycle reactor in the presence of various Pd-Cu and Pd-Sn bimetallic catalysts supported on alumina spheres with particle diameter of 1.7mm. It was discovered that Pd-Sn solids synthesized accordingly to various catalyst preparation methods, exhibit considerably lower activity for nitrate removal in comparison to Pd-Cu catalysts. Formation of undesired ammonium ions is favored over Pd-Sn/γ-Al2O3 catalysts prepared by impregnation and co-impregnation techniques. Acidity and textural properties of alumina supports as well as the presence of chloride ions in the catalyst–solution interface detrimentally influence catalytic performance in the process of liquid phase nitrate hydrogenation.