Ziyi Wang,Changyan Guo,Kefu Wang,Jiang Li,Jide Wang
Upgrading waste PET to prepare metal–organic frameworks (MOF) through chemical recycling provides new ideas and methods for PET recycling treatment and high value-added conversion. In this paper, Cobalt-based metal–organic frameworks (Co-MOF) were prepared from PET by one-pot solvothermal method without adding acids or bases. The prepared Co-MOF was used as a heterogeneous catalyst to catalyze the selective oxidation of ethylbenzene (EB) for the preparation of acetophenone (AP). When only tert-butyl hydroperoxide (TBHP) was used as the oxidizing agent without any additional solvents, 89% EB conversion and 94% AP selectivity were achieved, respectively. Moreover, the catalyst showed excellent stability with no significant deactivation under 5 cycles. In addition, the synthesized Co-MOF-10 also exhibits impressive conversion rates of 96% and 93% in benzyl alcohol and styrene oxidation, respectively. Compared with the Co-MOF prepared by commercial terephthalic acid (BDC), the Co-MOF-10 synthesized via the one-pot method using PET exhibits enhanced cost-effectiveness, environmental sustainability, and superior catalytic performance. The present study establishes a foundation for the conversion of plastic PET into valuable MOF and its subsequent application in C–H bond oxidation.
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 Co3O4 electrocatalysts (NiCo2O4) from spent LiCoO2 (SLCO), enabling sustainable PET upcycling to formic acid (FA) under economic conditions. The NiCo2O4 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/cm2 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 (Rct 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.
Hydrogen peroxide (H 2 O 2 ) electrosynthesis through oxygen reduction reaction (ORR) is drawing worldwide attention, whereas suffering seriously from the sluggish oxygen evolution reaction (OER) and the difficult extraction of thermodynamically unstable H 2 O 2 . Herein, we present an electrosynthesis protocol involving coupling ORR-to-H 2 O 2 with waste polyethylene terephthalate (PET) upcycling and the first H 2 O 2 conversion strategy. Ni-Mn bimetal- and onion carbon-based catalysts are designed to catalyze ORR-to-H 2 O 2 and ethylene glycol electrooxidation with the Faradaic efficiency of 97.5% (H 2 O 2 ) and 93.0% (formate). This electrolysis system runs successfully at only 0.927 V to achieve an industrial-scale current density of 400 mA cm −2 , surpassing all reported H 2 O 2 electrosynthesis systems. H 2 O 2 product is upgraded through two downstream routes of converting H 2 O 2 into sodium perborate and dibenzoyl peroxide. Techno-economic evolution highlights the high gross profit of the ORR || PET upcycling protocol over HER || PET upcycling and ORR || OER. This work provides an energy-saving methodology for the electrosynthesis of H 2 O 2 and other chemicals.
危险品化学品经营许可证（带存储）