Palladium Separation by Pd-Catalyzed Gel Formation via Alkyne Coupling
Palladium Separation by Pd-Catalyzed Gel Formation via Alkyne Coupling
复制标题
通过炔偶联形成钯催化凝胶来分离钯
DOI：
10.1021/acs.chemmater.9b02031
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发表时间：
2019
影响因子：
8.6
通讯作者：
Zhao Pengxiang
中科院分区：
文献类型：
--
作者：
Yang Xiaojiao;Chen Jinfan;Hu Liangsheng;Wei Jianyu;Shuai Maobin;Huang Deshun;Yue Guozong;Astruc Didier;Zhao Pengxiang
从含有多种金属的工业废物中选择性捕集贵金属是环境科学中最具挑战性的分支。已开发的方法如溶剂或固相萃取、离子交换、共沉淀、膜过滤和吸附依赖于螯合、静电吸引或离子交换，并且这些方法呈现有限的选择性并且需要后处理以用于进一步应用。本文报道了一种新颖的概念，涉及利用Pd的上级催化性能选择性地从其它金属中有效地捕获Pd。具体地，用炔基官能化的聚（乙烯醇）（PVA）的侧链使用Pd（II）催化二聚，其形成凝胶。Pd（II）离子被配位地封装到凝胶网络中，而其他金属离子被排除在网络之外，从而允许Pd的分离和固定。包埋的Pd（II）也被还原成Pd（0）纳米颗粒（PdNP），形成PdNPs@炔-PVA气凝胶，其对Suzuki-Miyaura交叉偶联反应表现出高催化活性。PdNPs@alkyne-PVA气凝胶被进一步修饰成PdNPs@C网络，用于高效的电化学析氢反应。该方法不仅提供了一种有效的方法来选择性地分离Pd，而且还提供了用于多种催化剂的捕获的Pd源，而无需进一步的后处理。
Selective entrapment of precious metals from industrial wastes containing various metals is a most challenging branch of environmental science. Developed methods like solvent or solid-phase extraction, ion exchange, co-precipitation, membrane filtration, and adsorption rely on chelation, electrostatic attraction, or ion exchange, and these methods present limited selectivity and require post-treatment for further application. Herein, an original concept is reported involving the utilization of the superior catalytic properties of Pd selectively for efficient entrapment of Pd from other metals. Specifically, side chains of poly(vinyl alcohol) (PVA) functionalized with alkynyl groups are catalytically dimerized using Pd(II), which forms gels. The Pd(II) ions are coordinatively encapsulated into the gel networks, while the other metal ions are excluded from the networks, thus allowing the separation and immobilization of Pd. The entrapped Pd(II) is also reduced to Pd(0) nanoparticles (PdNPs) forming PdNPs@alkyne-PVA aerogels that exhibit a high catalytic activity for the Suzuki–Miyaura cross-coupling reaction. PdNPs@alkyne-PVA aerogels are further carbonized to PdNPs@C networks for the efficient electrochemical hydrogen evolution reaction. This method provides an effective way not only to selectively separate Pd but also to utilize the entrapped Pd resources for multiple catalyses without further post-treatment of the entrapped Pd source.