Recovery of palladium from spent catalysts is of great practical significance for the construction of ecological civilization and resource recycling.However,for environmentally friendly adsorption methods,designing sp...Recovery of palladium from spent catalysts is of great practical significance for the construction of ecological civilization and resource recycling.However,for environmentally friendly adsorption methods,designing specialized capture vacancies with high capacity and precise selectivity for Pd(Ⅱ) ions remains a challenge.Herein,a salicylic acid-modified nanofiber(SANF),exhibiting specific spatial configuration and constructing a capture vacancy by "O-O" of hard bases,was designed and employed for recovering and separating palladium.The adsorption results indicated that the SANF exhibited a fast capture rate(reaching adsorption equilibrium within60 min) and a large capture capacity(about 170 mg/g) for Pd(Ⅱ) ions,and the capture process was exothermic and spontaneous.Additionally,the Lewis basicity of the capture vacancy after tuning better matches the Lewis acidity of Pd(Ⅱ) ions,which achieves a high-selectivity separation of Pd(Ⅱ) ions(selectivity coefficient for K(Ⅰ),Na(Ⅰ) Ca(Ⅱ),Mg(Ⅱ) and Al(Ⅲ) ions are 1505.2,10,536.7,1128.9,2634.2 and 2873.6,respectively).Practical applications showed that SANF was enabled to recover Pd(Ⅱ) ions from spent catalyst leachate and achieved four time adsorption-desorption cycles,possessing some industrial promise.Furthermore,the matching mechanism between the Lewis basicity of the capture vacancy and the Lewis acidity of the Pd(Ⅱ) ions was revealed through series characterization and theoretical calculations.Finally,it is proposed a Lewis basicity tuning strategy founded on a specific spatial structure,provides a new insight for the design and construction of a capture vacancy for Pd(Ⅱ) ions in the future.展开更多
以钯银合金废料为原料,采用硝酸溶解-盐酸沉银-二氯二氨络亚钯法提纯-水合肼还原工艺回收钯。结果表明,当浓盐酸用量为2 m L/200 m L混合酸液,反应时间1 h时,银沉淀率为99.98%;当氨络合和盐酸酸化沉淀过程溶液最佳p H分别为8和1.5,并经...以钯银合金废料为原料,采用硝酸溶解-盐酸沉银-二氯二氨络亚钯法提纯-水合肼还原工艺回收钯。结果表明,当浓盐酸用量为2 m L/200 m L混合酸液,反应时间1 h时,银沉淀率为99.98%;当氨络合和盐酸酸化沉淀过程溶液最佳p H分别为8和1.5,并经温水洗涤3次,二氯二氨络亚钯纯度达到99.99%以上;该工艺钯回收率大于90%,并制得纯度大于99.99%的海绵钯,其平均粒径不大于0.5μm。展开更多
基金supported by Sichuan Science and Technology Program(No.2024YFHZ0103)Anhui Province Applied Peak Cultivation Discipline(No.XK-XJGF005)+1 种基金Anhui Province Quartz Sand Purification and Photovoltaic Glass Engineering Research Center(No.[2022]547-49)the Key research and development projects of Shandong Province(No.2023CXGC010903).
文摘Recovery of palladium from spent catalysts is of great practical significance for the construction of ecological civilization and resource recycling.However,for environmentally friendly adsorption methods,designing specialized capture vacancies with high capacity and precise selectivity for Pd(Ⅱ) ions remains a challenge.Herein,a salicylic acid-modified nanofiber(SANF),exhibiting specific spatial configuration and constructing a capture vacancy by "O-O" of hard bases,was designed and employed for recovering and separating palladium.The adsorption results indicated that the SANF exhibited a fast capture rate(reaching adsorption equilibrium within60 min) and a large capture capacity(about 170 mg/g) for Pd(Ⅱ) ions,and the capture process was exothermic and spontaneous.Additionally,the Lewis basicity of the capture vacancy after tuning better matches the Lewis acidity of Pd(Ⅱ) ions,which achieves a high-selectivity separation of Pd(Ⅱ) ions(selectivity coefficient for K(Ⅰ),Na(Ⅰ) Ca(Ⅱ),Mg(Ⅱ) and Al(Ⅲ) ions are 1505.2,10,536.7,1128.9,2634.2 and 2873.6,respectively).Practical applications showed that SANF was enabled to recover Pd(Ⅱ) ions from spent catalyst leachate and achieved four time adsorption-desorption cycles,possessing some industrial promise.Furthermore,the matching mechanism between the Lewis basicity of the capture vacancy and the Lewis acidity of the Pd(Ⅱ) ions was revealed through series characterization and theoretical calculations.Finally,it is proposed a Lewis basicity tuning strategy founded on a specific spatial structure,provides a new insight for the design and construction of a capture vacancy for Pd(Ⅱ) ions in the future.
文摘以钯银合金废料为原料,采用硝酸溶解-盐酸沉银-二氯二氨络亚钯法提纯-水合肼还原工艺回收钯。结果表明,当浓盐酸用量为2 m L/200 m L混合酸液,反应时间1 h时,银沉淀率为99.98%;当氨络合和盐酸酸化沉淀过程溶液最佳p H分别为8和1.5,并经温水洗涤3次,二氯二氨络亚钯纯度达到99.99%以上;该工艺钯回收率大于90%,并制得纯度大于99.99%的海绵钯,其平均粒径不大于0.5μm。
