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

• 成果类型: Article
• 署名作者: Conk, Richard J.; Stahler, Jules F.; Shi, Jake X.; Yang, Ji; Lefton, Natalie G.; Brunn, John N.; Bell, Alexis T.; Hartwig, John F.
• 署名单位: University of California System; University of California Berkeley; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; University of California System; University of California Berkeley
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-13049
• DOI: 10.1126/science.adq7316
• 发表日期: 2024-09-20
• 页码: 1322-1327
• 关键词: low-temperature; polyethylene; metathesis; depolymerization; degradation; cracking; plastics

摘要

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 degrees C without the need for dehydrogenation of the starting polyolefins.