Studies on the feasibility of electrochemical recovery of palladium from high-level liquid waste
Studies on the feasibility of electrochemical recovery of palladium from high-level liquid waste
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DOI：
10.1016/j.electacta.2008.08.034
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发表时间：
2009
影响因子：
6.6
通讯作者：
M. Jayakumar;K. Venkatesan;T. Srinivasan;P. Rao
中科院分区：
文献类型：
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作者：
M. Jayakumar;K. Venkatesan;T. Srinivasan;P. Rao
用循环伏安法研究了钯(II)在硝酸介质中在铂电极和不锈钢电极上的电化学行为。循环伏安图显示在铂电极上的阴极电流在−0.1V(vs.Pd)处出现峰值，峰值出现在−0.3V处，这是由于Pd(II)还原为Pd所致。在扫描反转过程中，伴随着0.25V的宽窄阳极峰(IPA)。Pd(II)的还原是不可逆的，在298K时的扩散系数为2.35×10−8 cm~2/S。在不锈钢电极上，由于钯的沉积，在−0.4V(vs.Pd)处出现阴极电流激增，随后由于H+的还原，−在0.66V处的阴极电流急剧增加。在不锈钢电极上，从1M硝酸介质电解到4M硝酸介质中，可使钯完全回收，且有较高的法拉第效率(取决于硝酸浓度)。然而，在从模拟高放废液中电解的情况下，由于其他干扰竞争反应，回收率和法拉第效率显著降低(至40%)。
The electrochemical behavior of palladium (II) in nitric acid medium has been studied at platinum and stainless steel electrodes by cyclic voltammetry. The cyclic voltammogram consisted of a surge in cathodic current occurring at platinum electrode at a potential of −0.1V (vs. Pd), which culminates in a peak at −0.3V was due to the reduction of Pd(II) to Pd. This was accompanied by a broad scant anodic peak (Ipa) at 0.25V during scan reversal. Reduction of Pd(II) was irreversible and the diffusion coefficient was found to be 2.35×10−8cm2/s at 298K. At stainless steel electrode, a surge in the cathodic current occurring at −0.4V (vs. Pd) was due to palladium deposition, which was immediately followed by a steep increase in cathodic current at −0.66V due to H+reduction. Electrolysis of palladium nitrate from 1M to 4M nitric acid medium at stainless steel electrode resulted in complete recovery of palladium with reasonably high Faradaic efficiency depending upon nitric acid concentration. However, the recovery and Faradaic efficiency were significantly lowered (to 40%) in the case of electrolysis from simulated high-level liquid waste due to other interfering competitive reactions.