Abstract Rh extraction from spent auto-catalysts in an efficient and economical way is still an unresolved problem. In this work, the spent auto-catalyst samples were pretreated with O 2 , H 2 and CO under certain temperatures. After the pretreatments, the samples were leached with acidic sodium chlorate solutions to extract Rh. The Rh extraction for the sample without any pretreatment was 56%. The optimal temperature, time and flow rate of O 2 for the O 2 pretreatment were 300 °C, 3 h and 200 mL/min, respectively, and the Rh extraction under these conditions was 69%. Following O 2 pretreatment under optimal condition, H 2 or CO pretreatment was also carried out, respectively. The optimal temperature, time and flow rate of H 2 for the H 2 pretreatment were 300 °C, 3 h and 200 mL/min, respectively, and the Rh extraction in this case was 82% . The optimal temperature, time and flow rate of CO for the CO pretreatment were 300 °C, 1 h and 150 mL/min, respectively, and the Rh extraction in this case was 80% . In addition, the effects of pretreatment with H 2 and CO only on Rh extraction were also studied. It was found that pretreatment with O 2 only was more effective than pretreatment with H 2 and CO only, and O 2 pretreatment plus a following H 2 pretreatment was the most effective means to raise Rh extraction. Additionally, the possible mechanisms involved in pretreatment effects were also investigated.

中文翻译：

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O2、H2 和 CO 预处理对酸性氯酸钠溶液从废汽车催化剂中浸出 Rh 的影响

摘要 以高效、经济的方式从废汽车催化剂中提取 Rh 仍然是一个悬而未决的问题。在这项工作中，用过的汽车催化剂样品在一定温度下用 O 2 、H 2 和 CO 进行了预处理。预处理后，用酸性氯酸钠溶液浸出样品以提取Rh。未经任何预处理的样品的 Rh 提取率为 56%。O 2 预处理的最佳O 2 温度、时间和流速分别为300 °C、3 h 和200 mL/min，这些条件下的Rh 萃取率为69%。在优化条件下O 2 预处理后，还分别进行H 2 或CO 预处理。H 2 预处理的最佳H 2 温度、时间和流速分别为300 °C、3 h 和200 mL/min，此时Rh 提取率为82%。CO 预处理的最佳温度、时间和 CO 流速分别为 300 °C、1 h 和 150 mL/min，在这种情况下，Rh 提取率为 80%。此外，还研究了仅用H 2 和CO 预处理对Rh 提取的影响。发现仅用O 2 预处理比仅用H 2 和CO 预处理更有效，并且O 2 预处理加上随后的H 2 预处理是提高Rh提取率的最有效手段。此外，还研究了预处理效果所涉及的可能机制。发现仅用O 2 预处理比仅用H 2 和CO 预处理更有效，并且O 2 预处理加上随后的H 2 预处理是提高Rh提取率的最有效手段。此外，还研究了预处理效果所涉及的可能机制。发现仅用O 2 预处理比仅用H 2 和CO 预处理更有效，并且O 2 预处理加上随后的H 2 预处理是提高Rh提取率的最有效手段。此外，还研究了预处理效果所涉及的可能机制。