Effects of anions on the kinetics and reactivity of nanoscale Pd/Fe in trichlorobenzene dechlorination
Effects of anions on the kinetics and reactivity of nanoscale Pd/Fe in trichlorobenzene dechlorination
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DOI：
10.1016/j.chemosphere.2008.07.050
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发表时间：
2008-11-01
期刊：
影响因子：
8.8
通讯作者：
Zhu, Bao-Wei
中科院分区：
文献类型：
--
作者：
Lim, Teik-Thye;Zhu, Bao-Wei
在硝酸盐、亚硝酸盐、高氯酸盐、磷酸盐、碳酸盐、二氧化硅、硫酸盐、亚硫酸盐或硫化物等阴离子溶质存在下，通过批量实验研究了阴离子共溶质对纳米级 Pd/Fe 颗粒对 1,2,4-三氯苯 (124TCB) 脱氯的影响。根据对124TCB脱氯的抑制作用程度，可将阴离子按以下顺序排列。控制 近似硫酸盐 近似二氧化硅 < 高氯酸盐 < 碳酸盐 < 硝酸盐 < 磷酸盐 < 亚硝酸盐 < 亚硫酸盐 < 硫化物。对新鲜和反应后的 Pd/Fe 样品进行 XRD 矿物学分析、SEM-EDX 形态研究以及 FTIR 光谱仪光谱分析，以检查各种阴离子对 Pd/Fe 表面的影响。二氧化硅和硫酸盐对颗粒状 Pd/Fe 的反应性没有表现出任何显着的短期影响，因为 124TCB 脱氯反应仅依赖于 Id 位点的反应性，而 Id 位点显然没有被阴离子钝化。然而，硫化物和亚硫酸盐可以立即终止124TCB脱氯过程。根据其对 Pd/Fe 124TCB 脱氯抑制作用的性质，阴离子可分为：（1）吸附沉淀钝化物种（如磷酸盐和碳酸根），（2）氧化还原活性物种（如硝酸盐、亚硝酸盐和高氯酸盐），以及（3）催化剂毒物（如硫化物和亚硫酸盐）。 (C) 2008 Elsevier Ltd. 保留所有权利。
Influences of anionic co-solutes on dechlorination of 1,2,4-trichlorobenzene (124TCB) by the nanoscale Pd/Fe particles were investigated in batch experiments in the presence of an anionic solute such as nitrate, nitrite, perchlorate, phosphate, carbonate, silica, sulfate, sulfite, or sulfide. Based on the extent of inhibitory effects on the 124TCB dechlorination, the anions can be ranked in the order of. control approximate to sulfate approximate to silica < perchlorate < carbonate < nitrate < phosphate < nitrite < sulfite < sulfide. Mineralogical analysis with XRD, morphological study with SEM-EDX, and spectroscopic analysis with FTIR spectrometer of the fresh and reacted Pd/Fe samples were conducted to examine the influences of the various anions on the Pd/Fe surface. Silica and sulfate did not show any significant short-term effect on reactivity of the ramoscale Pd/Fe, because the 124TCB dechlorination reaction was only dependent on the reactivity of the I'd site that was apparently not passivated by the anions. However, sulfide and sulfite could immediately terminate the 124TCB dechlorination process. Based on the natures of their inhibitory effects on 124TCB dechlorination by the Pd/Fe, the anions can be classified as: (1) adsorption-precipitation passivating species (e.g., phosphate and carbonate), (2) redox-active species (e.g., nitrate, nitrite, and perchlorate), and (3) catalyst poisons (e.g., sulfide and sulfite). (C) 2008 Elsevier Ltd. All rights reserved.