PdAg Alloy Nanocatalysts: Toward Economically Viable Nitrite Reduction in Drinking Water
PdAg Alloy Nanocatalysts: Toward Economically Viable Nitrite Reduction in Drinking Water
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DOI：
10.1021/acscatal.0c01538
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发表时间：
2020-07-17
期刊：
影响因子：
12.9
通讯作者：
Werth, Charles J.
中科院分区：
文献类型：
--
作者：
Troutman, Jacob P.;Li, Hao;Werth, Charles J.
硝酸盐（NO3-）是全球淡水中最主要的污染物，亚硝酸盐（NO2-）是硝酸盐（NO3-）的主要还原产物。这两个物种都面临着主要的环境挑战；二氧化氮对人类也有很高的毒性。从饮用水中去除NO3-和NO2-的现有技术受到许多问题的阻碍，这些问题限制了它们的广泛使用。催化降解NO3-和NO2-是一项潜在的颠覆性技术。然而，该工艺所需的钯金属的高成本是一个重大的经济障碍。在此，我们报道了基于随机合金钯银纳米颗粒的可伸缩催化剂材料的合成。这些催化剂显著降低了催化剂的总成本，同时使NO2-加氢还原的催化活性提高了3.4倍。密度泛函理论（DFT）研究表明，钯与银的合金化产生了更有利的表面结合位点，这是催化活性提高的原因。这些催化剂在产生氮气而不是氨方面也具有很高的选择性。
Nitrite (NO2-) is the primary reduction product of nitrate (NO3-), which is the most predominant contaminant in global freshwater. Both species present major environmental challenges; NO2- is also highly toxic to humans. Available technologies for the removal of NO3- and NO2- from potable water are hampered by a number of issues, which limit their widespread usage. Catalytic degradation of NO3- and NO2- is a potentially disruptive technology. However, the high cost of palladium metal required for this process is a significant economic barrier. Herein, we report the synthesis of scalable catalyst materials based on randomly alloyed palladium-silver nanoparticles. These catalysts significantly lower the overall catalyst cost and simultaneously achieve a 3.4-times increase in the catalytic activity for NO2- hydrogenative reduction. Density functional theory (DFT) studies reveal that alloying Pd with Ag creates more favorable surface binding sites, which is the origin of the increased catalytic activity. The catalysts are also highly selective toward the production of nitrogen gas over ammonia.