Chen Zhaoxi, Zhang Gaige, Yang Huayue, Zhao Yun, Pei An, Wang Peng, Yang Jin, Zhang Junxi, Sun Peilin, Qin Haohang, Zhan Junzheng, Peng Jian, Huang Wei-Hsiang, Zhou Linan, Chen Guangxu
School of Environment and Energy, State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou 510006, China.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P R China.
ACS Nano. 2025 Jul 29;19(29):26572-26582. doi: 10.1021/acsnano.5c05213. Epub 2025 Jul 16.
The electrochemical upcycling of polyethylene terephthalate (PET) into high-value products is essential for tackling "white pollution" and enhancing environmental protection. However, significant challenges remain, including the need for low-cost, highly efficient electrocatalysts, and the expensive electrolyte recovery in alkaline systems. This study presents a simple doping method to produce Ni octahedral-doped CoO electrocatalysts (NiCoO) from spent LiCoO (SLCO), enabling sustainable PET upcycling to formic acid (FA) under economic conditions. The NiCoO catalyst exhibits outstanding electrocatalytic activity for the ethylene glycol oxidation reaction (EGOR), achieving a Faradaic efficiency of 90.5% for FA at a potential of 1.50 V versus RHE. When integrated into an anion-exchange membrane (AEM) reactor, the system displayed an average current density of 173.5 mA/cm and a Faradaic efficiency of 84.7% at a cell voltage of 1.70 V. Systematic characterizations and DFT calculations indicate that Ni doping alters the spin-state electron density of Co, increases the localized electrons around Co sites, and significantly reduces the charge transfer resistance ( from 44.10 Ω to 10.23 Ω) of EGOR. Moreover, the Co-Ni dual sites enhance EG adsorption compared to individual Co or Ni sites. Finally, along with our electrochemical recovery and separation system (ERSS), a KOH recovery rate of 98.9% is achieved, yielding a return of $440.50 per ton of recycled PET─approximately a 4-fold profit increase compared to the traditional acid-base neutralization process (ABNP). This work describes a closed-loop model that simultaneously addresses battery recycling, plastic pollution reduction, and eco-friendly chemical production.
将聚对苯二甲酸乙二酯（PET）电化学升级循环为高价值产品对于应对“白色污染”和加强环境保护至关重要。然而，仍存在重大挑战，包括需要低成本、高效的电催化剂，以及碱性体系中昂贵的电解质回收问题。本研究提出了一种简单的掺杂方法，用废LiCoO（SLCO）制备八面体镍掺杂的CoO电催化剂（NiCoO），从而在经济条件下实现PET可持续升级循环生成甲酸（FA）。NiCoO催化剂对乙二醇氧化反应（EGOR）表现出出色的电催化活性，在相对于可逆氢电极（RHE）为1.50 V的电位下，FA的法拉第效率达到90.5%。当集成到阴离子交换膜（AEM）反应器中时，该系统在1.70 V的电池电压下显示出173.5 mA/cm的平均电流密度和84.7%的法拉第效率。系统表征和密度泛函理论（DFT）计算表明，镍掺杂改变了钴的自旋态电子密度，增加了钴位点周围的局域电子，并显著降低了EGOR的电荷转移电阻（从44.10 Ω降至10.23 Ω）。此外，与单个钴或镍位点相比，钴 - 镍双位点增强了乙二醇（EG）的吸附。最后，连同我们的电化学回收与分离系统（ERSS），实现了98.9%的KOH回收率，每吨回收PET可产生440.50美元的收益 ── 与传统酸碱中和工艺（ABNP）相比，利润增加了约4倍。这项工作描述了一个同时解决电池回收、减少塑料污染和环保化学品生产问题的闭环模型。
