Amination of polylactic acid to alanine using a Ru–Co bimetallic catalyst

Abstract

The preparation of alanine from waste polylactic acid (PLA) is not only an effective way to recycle waste plastics, but also of great significance to develop a green, clean and...

Chemical Upcycling of Polylactic Acid Plastic Waste into Alanine over Ru/CeO2 with Decoration of Indium

“…The time–course profile revealed that the yield of alanine acid rose almost linearly from 18.4 to 66.7% as the reaction time was extended from 1 to 10 h, while other byproducts, such as ammonium lactate and lactamide, decreased from 73.8 to 31.6% and 7.1 to 6.4%, respectively (Figure b). This suggests that ammonium lactate and lactamide should serve as the key intermediates in the amination of PLA to alanine . However, during the subsequent 8 h, the yield of alanine showed a slight increase from 66.7 to 76.1%, suggesting that the yield of alanine reached a plateau after an initial rapid increase.…”

“…This suggests that ammonium lactate and lactamide should serve as the key intermediates in the amination of PLA to alanine. 13 However, during the subsequent 8 h, the yield of alanine showed a slight increase from 66.7 to 76.1%, suggesting that the yield of alanine reached a plateau after an initial rapid increase. Additionally, prolonging the reaction time beyond 18 h resulted in a gradual increase in the alanine yield.…”

“…The catalytic system significantly accelerated the reaction efficiency of PLA waste through the chemical upgrading process, achieving a high alanine production rate of up to 3.01 mol Ala •mol Ru −1 •h −1 , together with exceptional stability of the catalyst, surpassing previously reported catalysts by a significant margin. 13,28 Multiple characterization techniques and experimental results embodied that the Ru/CeO 2 with decoration of In significantly enhanced the surface area and Ce 3+ /(Ce 3+ + Ce 4+ ) ratio, generated abundant oxygen vacancies, and increased the surface basicity, consequently resulting in a remarkable improvement in catalytic activity, alanine selectivity, and recyclability of catalyst. This research suggests that Ru/CeO 2 with decoration of In has great Catalyst Preparation.…”

“…Thus, it is instant in demand of exploiting more appealing strategies for closing the carbon loop and meet the carbon-neutral challenge through efficient recycling technologies of PLA toward the establishment of circular economy and achievement of carbon neutrality. 12,13 Amino acids as the fundamental building blocks of life proteins have a wide range of application in various fields. 14−19 In particular, alanine stands out as one of the most important amino acids and is widely utilized in food, agriculture, biodegradable plastics, and pharmaceutical industries.…”

“…Hence, achievement of carbon neutrality is of paramount importance. − Polylactic acid (PLA), as a biobased and biodegradable polyester, is considered to be one of the most prominent representatives of replacing traditional petroleum-based plastics, which is extensively applied in various fields including packaging, textiles, and biomedical products. − Currently, PLA production has reached 0.9 million tonnes per year, resulting in a considerable amount of PLA wastes that urgently need to be disposed or recycled effectively. , Although PLA can undergo spontaneous decomposition in nature, the process of breaking down PLA into H 2 O and CO 2 is slow and requires specific environmental conditions to proceed efficiently. Thus, it is instant in demand of exploiting more appealing strategies for closing the carbon loop and meet the carbon-neutral challenge through efficient recycling technologies of PLA toward the establishment of circular economy and achievement of carbon neutrality. , …”