Issue 7, 2024

Beyond biodegradation: upcycling of polylactic acid plastic waste into amino acids via cascade catalysis under mild conditions

Abstract

Biodegradable plastics, represented by polylactic acid (PLA), are considered suitable alternatives to non-degradable commodity plastics; however, their degradation through microbial decomposition is seen as a waste of carbon resources and inevitably brings about CO2 emission. Alternatively, waste PLA plastics can be utilized as feedstocks for the sustainable production of value-added chemicals, which not only avoids a carbon footprint but also realizes upcycling of plastic waste. Here, we show a cascade system that combines alkali-induced depolymerization, pulsed electrooxidation, and electrochemical reductive amination to produce alanine with an overall yield of 69% under near ambient conditions. Specifically, we first implement an alkali catalyst in an aqueous solution to depolymerize PLA into lactate. The obtained PLA hydrolysate is directly utilized as both feedstock and electrolyte for pyruvate production over a nickel hydroxide-supported Pd electrocatalyst (Pd/Ni(OH)2) via a pulsed potential, which is followed by the transformation of pyruvate into alanine using a TiO2 catalyst. This cascade process for alanine production benefits from high efficiencies maintained in three consecutive processes, mild operation conditions, and the use of cost-effective feedstocks (plastic wastes), without suffering harsh conditions and expensive feedstock consumption required by conventional biological and chemical approaches for alanine synthesis, respectively.

Graphical abstract: Beyond biodegradation: upcycling of polylactic acid plastic waste into amino acids via cascade catalysis under mild conditions

Supplementary files

Article information

Article type
Paper
Submitted
17 Nov 2023
Accepted
16 Feb 2024
First published
19 Feb 2024

Green Chem., 2024,26, 3995-4004

Beyond biodegradation: upcycling of polylactic acid plastic waste into amino acids via cascade catalysis under mild conditions

Y. Ma, X. Guo, M. Du, S. Kang, W. Dong, V. Nicolosi, Z. Cui, Y. Zhang and B. Qiu, Green Chem., 2024, 26, 3995 DOI: 10.1039/D3GC04460B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements