燃料电池电堆EOL后贵金属回收料直接制备克级铂碳催化剂Gram－size Pt／C catalyst synthesized using Pt compound directly recovered from an end－of－life PEM fuel cell stackMaterials Chemistry and Physics

Volume 276， 15 January 2022， 125439

Muralidhar Chourashiya
Raghunandan Sharma
Saso Gyergyek
Shuang MaAndersen

这篇文章中出现了一所我从来没有听说过的院校Guangdong Technion – Israel Institute of Technology广东以色列理工学院。

这篇文章的思路很简单，就是把废旧电堆电极中的Pt直接转化为H2PtCl6，再使用EG法还原制备催化剂。

Abstract
The proton exchange membrane fuel cell （PEMFC） technology is getting closer to its maturity． However， the use of PEMFCs in fuel cell vehicles needs to tackle the challenges arising from insufficient durability and the high cost of catalysts， leading to the accumulation of high－price waste from the end－of－life fuel cell stacks． The use of this waste as a secondary source of platinum can be more economic and environmentally friendly compared to its primary production． In this investigation， platinum from the end－of－life fuel cell stack is recycled as a fresh Pt／C catalyst． The recycling processes involved the dissolution of Pt from the end－of－life fuel cell electrodes by refluxing in dilute acid （1 M HCl）， followed by drying the Pt solution in a rotary evaporator and using the dried－Pt precursor for polyol synthesis of Pt／C． With the aim of their industrial adaptation， a gram－scale synthesis of Pt／C using the polyol method is carried out and its electrocatalytic performance is compared with commercial benchmark catalysts． Electrochemical performances of the Pt／C electrocatalysts synthesized using the recycled Pt and the equivalent commercial Pt precursor are found to be comparable．

使用回收得到的H2PtCl6和商品H2PtCl66H2O的对比试验。

铂回收前后催化剂上铂的状态。

回收得到的H2PtCl6和商品H2PtCl66H2O的光谱对比。

XRD对比

回收得到的H2PtCl6和商品H2PtCl66H2O的制作的催化剂样品的对比，但是对比图并不是同一个操作条件下制作的。

回收得到的H2PtCl6和商品H2PtCl66H2O的制作的催化剂样品的CV对比。回收得到的H2PtCl6的铂吸附脱附峰似乎更加显著。

文中关于双电层的讨论定量的说明太少， 图那么小又不提供定量数据说服力少一些，还不如对回收得到的H2PtCl6做一下表征，有多少残余的碳材料混入原料。

回收得到的H2PtCl6制作的催化剂样品 LSV实验似乎有些问题。

但是电位循环的耐久性相比于商品化产品有优势。

失效后的燃料电池电堆电极是个富矿，讨论铂的回收现在还不晚也很有意义。

但是文章统计一下回收率和技术经济学就更有意义一些。

大批量催化剂的制备并非看看性能那么简单，产物中杂质的含量控制等难度也会因为是回收料而增大。

Conclusions

The investigation shows that the platinum from the end－of－life fuel
cell stack is successfully recycled as a fresh Pt／C catalyst． The polyol
method， upon optimization， can enable the large batch of Pt／C catalyst
synthesis by the virtue of two－step synthesis， namely， colloid formation
step and deposition on support step． The simple Pt extraction procedure and drying of extracted solution using a rotary evaporator （enabling recovery of extraction media） prompt that the outlined procedure is favorable for industrial adaptation， though it demands further optimization for energy efficiency． Furthermore， it was observed that for a time／energy－efficient synthesis， using the polyol method， the microwave reactors with reactant stirring arrangements can be the best
option．

The ECSA value of recycled platinum as fresh Pt／C catalysts is 60 m2／
g which closely matches with that of the catalyst synthesized using
commercial Pt precursor （62 m2／g）． However， by comparing the cyclic
voltammograms of Pt／C synthesized using dried Pt precursor and commercial Pt precursor it was observed the earlier exhibited relatively
more DLCs which can be attributed to the presence of residual carbon in the dried Pt precursor which propagated to the final product． The residual carbon was also observed to affect the final Pt loading on carbon supports． On the other hand， residual carbon in the dried Pt precursor provided immunity from the agglomeration of Pt nanoparticles during their synthesis while it was not the case for commercial Pt precursors． Finally， the Pt／C catalyst synthesized using dried Pt precursor showed relatively better durability than that of commercial benchmark catalysts i．e．， HiSpec9100 and BASF 20％ Pt／C．