The inert carbon–carbon(C–C) bonds cleavage is a main bottleneck in the chemical upcycling of recalcitrant polyolefin plastics waste. Here we develop an efficient strategy to catalyze the complete cleavage of C–C b...The inert carbon–carbon(C–C) bonds cleavage is a main bottleneck in the chemical upcycling of recalcitrant polyolefin plastics waste. Here we develop an efficient strategy to catalyze the complete cleavage of C–C bonds in mixed polyolefin plastics over non-noble metal catalysts under mild conditions. The nickelbased catalyst involving Ni_(2)Al_(3) phase enables the direct transformation of mixed polyolefin plastics into natural gas, and the gas carbon yield reaches up to 89.6%. Reaction pathway investigation reveals that natural gas comes from the stepwise catalytic cleavage of C–C bonds in polypropylene, and the catalyst prefers catalytic cleavage of terminal C–C bond in the side-chain with the low energy barrier.Additionally, our developed approach is evaluated by the technical economic analysis for an economically competitive production process.展开更多
The rapid accumulation of plastic waste poses severe environmental challenges.Cold plasma-driven degradation offers a promising route to convert plastic waste into high-value chemicals.In this study,a singlestage plas...The rapid accumulation of plastic waste poses severe environmental challenges.Cold plasma-driven degradation offers a promising route to convert plastic waste into high-value chemicals.In this study,a singlestage plasma reactor coupling cold plasma(dielectric barrier discharge)with Hβ zeolites was developed for polyethylene degradation under relatively mild conditions,without external thermal input or participation of noble metals.The effects of zeolite pore structure and acidity toward product distribution were investigated,revealing that Hβ-25 exhibited the highest C_(1)-C_(6) yield(76 wt%)and a space-time yield of 103.8 mmol·g_(cat)^(-1)·h^(-1) compared to other zeolite catalysts during the plasma-catalytic process.Meanwhile,it was revealed that efficient precracking initiated by plasma activation and the optimal structural compatibility between Hβ-zeolite pore channels and primary cracking products were the key factors enabling the selective conversion of polyethylene into C_(1)-C_(6) hydrocarbons.Additionally,metal incorporation significantly enhanced C-H bond cleavage compared to Hβ-25 support.Especially,10Ni/Hβ-25 exhibited the highest hydrogen yield(7.87 mmol·g_(plastic)^(-1))under plasmaassisted mode,markedly surpassing its yield under thermal-cracking conditions,demonstrating the significant potential of plasma-catalytic degradation for hydrogen production from polyethylene.展开更多
基金supported by the National Natural Science Foundation of China (grant 22208339)the China Postdoctoral Science Foundation (2021M693132)+2 种基金the National Key R&D Program of China (2019YFC1905303)the Doctoral Scientific Research Foundation of Liaoning Province (2021-BS-006)the Youth Innovation Fund of Dalian Institute of Chemical Physics (DICP I202132)。
文摘The inert carbon–carbon(C–C) bonds cleavage is a main bottleneck in the chemical upcycling of recalcitrant polyolefin plastics waste. Here we develop an efficient strategy to catalyze the complete cleavage of C–C bonds in mixed polyolefin plastics over non-noble metal catalysts under mild conditions. The nickelbased catalyst involving Ni_(2)Al_(3) phase enables the direct transformation of mixed polyolefin plastics into natural gas, and the gas carbon yield reaches up to 89.6%. Reaction pathway investigation reveals that natural gas comes from the stepwise catalytic cleavage of C–C bonds in polypropylene, and the catalyst prefers catalytic cleavage of terminal C–C bond in the side-chain with the low energy barrier.Additionally, our developed approach is evaluated by the technical economic analysis for an economically competitive production process.
基金financially supported by the National Key R&D Program of China(Grant Nos.2023YFA1506602 and 2021YFA1501102)the National Natural Science Foundation of China(Grant Nos.21932002,22276023,and 22402019)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.DUT22LAB602)the Liaoning Binhai Laboratory Project(Grant No.LBLF-202306).
文摘The rapid accumulation of plastic waste poses severe environmental challenges.Cold plasma-driven degradation offers a promising route to convert plastic waste into high-value chemicals.In this study,a singlestage plasma reactor coupling cold plasma(dielectric barrier discharge)with Hβ zeolites was developed for polyethylene degradation under relatively mild conditions,without external thermal input or participation of noble metals.The effects of zeolite pore structure and acidity toward product distribution were investigated,revealing that Hβ-25 exhibited the highest C_(1)-C_(6) yield(76 wt%)and a space-time yield of 103.8 mmol·g_(cat)^(-1)·h^(-1) compared to other zeolite catalysts during the plasma-catalytic process.Meanwhile,it was revealed that efficient precracking initiated by plasma activation and the optimal structural compatibility between Hβ-zeolite pore channels and primary cracking products were the key factors enabling the selective conversion of polyethylene into C_(1)-C_(6) hydrocarbons.Additionally,metal incorporation significantly enhanced C-H bond cleavage compared to Hβ-25 support.Especially,10Ni/Hβ-25 exhibited the highest hydrogen yield(7.87 mmol·g_(plastic)^(-1))under plasmaassisted mode,markedly surpassing its yield under thermal-cracking conditions,demonstrating the significant potential of plasma-catalytic degradation for hydrogen production from polyethylene.
