This work studies catalytic reduction of nitrate with bimetallic catalysts supported on γ-alumina (Pd-Sn/Al₂O₃ and Pd-In/Al₂O₃). Pd-Sn/Al₂O₃ yielded higher NO₃⁻ conversion and selectivity towards N₂ than Pd-In/Al₂O₃ in synthetic water (deionized water with 100 mg/L NO₃⁻). The Pd-Sn/Al₂O₃ catalyst showed highly stable behaviour, without signs of deactivation upon ten consecutive runs of 6 h each, where almost equal low selectivity to NH₄⁺ (absence of NO₂⁻) was maintained at high nearly constant nitrate conversion (≈ 90%). The presence of anions (Cl⁻, SO₄²⁻ and HCO₃⁻) in the reaction medium decreased NO₃⁻ conversion and the selectivity towards N₂. Chloride showed a moderately negative effect at relatively low concentration. The effect of SO₄²⁻ and HCO₃⁻ was more pronounced, being the second the most detrimental to the catalytic activity. The selectivity towards N₂ was also negatively affected by the presence of those anions following the sequence HCO₃⁻ > SO₄²⁻ > Cl⁻. However, the joint presence of Cl⁻ or SO₄²⁻ with HCO₃⁻ reduced the negative effect of the latter. The Pd-Sn/Al₂O₃ catalyst also showed high activity in NO₃⁻ reduction from drinking waters of weak mineralization, with a slightly increase of the selectivity towards NH₄⁺ with respect to the obtained in deionized water with NO₃⁻ as the only anion.

这项工作研究了负载在γ-氧化铝上的双金属催化剂（Pd-Sn / Al ₂ O ₃和Pd-In / Al ₂ O ₃）对硝酸盐的催化还原。的Pd-Sn系/ Al的₂ ö ₃得到更高NO ₃ ^-转化率和选择性朝Ñ ₂除Pd-IN /的Al ₂ ö ₃中合成的水（去离子水与100毫克/升NO ₃ ^- ）。Pd-Sn / Al ₂ O ₃催化剂表现出高度稳定的行为，每十次连续运行6h时均没有失活的迹象，其中对NH ₄ ^+的选择性几乎相等（不存在NO的₂ ^- ）维持在高几乎恒定的硝酸转化率（≈90％）。阴离子的存在（CL ^-，SO ₄ ^2-和HCO ₃ ^- ）在反应介质中降低NO ₃ ^-转化率和朝向n中的选择性₂。氯化物在相对较低的浓度下显示出中等程度的负面影响。SO的效果₄ ^2-和HCO ₃ ^-更加明显，是第二最不利的催化活性。遵循序列HCO ₃的那些阴离子的存在也对N ₂的选择性产生负面影响^- > SO ₄ ^2- >氯^-。然而，Cl组成的联合存在^-或SO ₄ ^2-与HCO ₃ ^-降低后者的负面影响。将Pd-Sn系/ Al的₂ ö ₃催化剂也表现出NO高活性₃ ^-从饮用弱矿化的水域，具有稍微朝着NH提高选择性的还原₄ ⁺相对于在去离子水中用NO所获得的₃ ^-为唯一的阴离子。