美国加州大学John F. Hartwig团队报道了用乙烯和贱金属非均相催化剂将废旧聚烯烃转化为轻烯烃。相关研究成果发表在2024年8月29日出版的国际学术期刊《科学》。

目前，迫切需要聚乙烯、聚丙烯和这两种聚合物的混合物的选择性转化，以形成需求量大的产品，因为目前的方法选择性低，产生大量温室气体，或者依赖于昂贵的一次性催化剂。

不饱和聚烯烃的异构化乙烯醇解可能是一种，在能量和环境上可行的制备丙烯和异丁烯的方法，但目前需要贵金属均相催化剂和不饱和聚烯烃，而且该方法仅限于聚乙烯。

研究表明，氧化钨在二氧化硅上和钠在γ氧化铝上的简单组合，可以在320°C下将聚乙烯、聚丙烯或两者的混合物（包括这些材料的消费后形式），转化为丙烯或丙烯和异丁烯的混合物，产率大于90%，而不需要对起始聚烯烃进行脱氢。

附：英文原文

Title: Polyolefin waste to light olefins with ethylene and base-metal heterogeneous catalysts

Author: Richard J. Conk, Jules F. Stahler, Jake X Shi, Ji Yang, Natalie G. Lefton, John N. Brunn, Alexis T. Bell, John F. Hartwig

Issue&Volume: 2024-08-29

Abstract: The selective conversion of polyethylene, polypropylene, and mixtures of the two polymers to form products with high volume demand is urgently needed because current methods suffer from low selectivity, produce large quantities of greenhouse gases, or rely on expensive, single-use catalysts. The isomerizing ethenolysis of unsaturated polyolefins could be an energetically and environmentally viable route to propylene and isobutylene, but noble-metal homogeneous catalysts and an unsaturated polyolefin are currently required, and the process has been limited to polyethylene. We show that the simple combination of tungsten oxide on silica and sodium on gamma-alumina transforms polyethylene, polypropylene, or a mixture of the two, including post-consumer forms of these materials, to propylene or a mixture of propylene and isobutylene in greater than 90% yield at 320°C without the need for dehydrogenation of the starting polyolefins.

DOI: adq7316

Source: https://www.science.org/doi/10.1126/science.adq7316