Conk Richard J, Stahler Jules F, Shi Jake X, Yang Ji, Lefton Natalie G, Brunn John N, Bell Alexis T, Hartwig John F
Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA.
Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Science. 2024 Sep 20;385(6715):1322-1327. doi: 10.1126/science.adq7316. Epub 2024 Aug 29.
The selective conversion of polyethylene (PE), polypropylene (PP), and mixtures of these 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; however, noble-metal homogeneous catalysts and an unsaturated polyolefin are currently required and the process has been limited to PE. We show that the simple combination of tungsten oxide on silica and sodium on gamma-alumina transforms PE, PP, or a mixture of the two, including postconsumer 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.
迫切需要将聚乙烯（PE）、聚丙烯（PP）以及这两种聚合物的混合物选择性转化为具有高市场需求的产品，因为目前的方法存在选择性低、产生大量温室气体或依赖昂贵的一次性催化剂等问题。不饱和聚烯烃的异构化乙烯解可能是一种在能源和环境方面可行的制备丙烯和异丁烯的途径；然而，目前需要贵金属均相催化剂和不饱和聚烯烃，并且该过程仅限于PE。我们表明，二氧化硅负载的氧化钨和γ-氧化铝负载的钠的简单组合，可在320°C下将PE、PP或两者的混合物（包括这些材料的消费后形式）转化为丙烯或丙烯与异丁烯的混合物，产率大于90%，且无需起始聚烯烃脱氢。
