Cold plasma-assisted catalytic upcycling of polyolefin wastes integrated with CO_(2)into value-added chemicals is a promising solution for mitigating the global carbon emissions and fossil energy crisis,but still chal...Cold plasma-assisted catalytic upcycling of polyolefin wastes integrated with CO_(2)into value-added chemicals is a promising solution for mitigating the global carbon emissions and fossil energy crisis,but still challenging due to the complexity of products and low energy efficiency.Given this,a novel one-stage process of cold plasma coupled with Ga-modified hierarchical H-ZSM-5(Ga/Hie-ZSM-5)catalyst for polyolefins upgrading was designed with polyolefins followed by the catalysts within the plasma region,which facilitated the upcycling of polyolefins to light olefins and CO_(2)activation by plasma,and thereby the enhanced synergy between cold plasma and catalysts for aromatics production.At an input power of ca.45 W without external heating,the low-density polyethylene(LDPE)waste was completely converted with the assistance of CO_(2)and the yield of oil products over the Ga/Hie-ZSM-5 catalyst was highly up to 62.2 wt%,with nearly 100% selectivity of aromatics.Meanwhile,the degradation efficiency of LDPE and the energy efficiency could reach 2.5 g_(LDPE)·g_(cat)^(-1)·h^(-1)and 55.56 g_(LDPE)·g_(cat)^(-1)·kW^(-1)h^(-1),respectively.Mechanism investigation revealed that the plasma and CO_(2)synergistically affect the primary cracking of LDPE,forming a primary product enriched in olefins and a small amount of CO.Subsequently,the produced olefins intermediates were further aromatized via cyclizationdehydrogenation route on the Ga/Hie-ZSM-5 catalyst with assistance of CO_(2)under the synergistic effect of plasma-catalysis.This work offers a feasible strategy to improve the yield of aromatic products for the plasma-catalytic upcycling of polyolefins and CO_(2)at ambient pressure without any external heating.展开更多
The crystallization behavior of two commercial polyolefin elastomer(POE)samples was investigated using the fast scanning chip calorimetry(FSC)technique.Non-isothermal crystallization of the POE samples during cooling ...The crystallization behavior of two commercial polyolefin elastomer(POE)samples was investigated using the fast scanning chip calorimetry(FSC)technique.Non-isothermal crystallization of the POE samples during cooling to low temperatures cannot be inhibited under the largest efficient cooling rate employed in the current work.Thus,the isothermal crystallization of POE samples was limited to a narrow temperature range.When the POE samples were cooled to a certain temperature below the non-isothermal crystallization temperature for crystallization,a crystallization time dependent melting peak appeared in the low temperature region besides the high temperature melting peak originated from the non-isothermal crystallization.This low temperature melting peak was arisen from the melting of crystals isothermally crystallized at the selected crystallization temperature.At each crystallization temperature,the lengths of crystallizable segments were different,thus,the low melting peak increased with increasing the crystallization temperature.In terms of the high melting peak attributed to the non-isothermally crystallized crystals,it somehow decreased with increasing crystallization time and then became constant with further increasing crystallization time at the selected crystallization temperature.This could be explained by the fact that the crystallizable sequences with longer length would nucleate and crystallize first to form thicker crystals during cooling.The subsequent crystallization contributed by the shorter crystallizable sequences will result in the formation of thinner crystals,causing the melting peak to shift to the lower temperature.展开更多
目前商用聚烯烃隔膜存在电解液亲和性和热稳定性差等问题,导致所组装电池的充放电性能和安全性有所欠缺。为改善电解液的亲和性及热稳定性,采用聚乙烯醇为黏结剂将纳米碳酸钙涂覆至聚丙烯隔膜表面,通过扫描电子显微镜、电化学测试、热...目前商用聚烯烃隔膜存在电解液亲和性和热稳定性差等问题,导致所组装电池的充放电性能和安全性有所欠缺。为改善电解液的亲和性及热稳定性,采用聚乙烯醇为黏结剂将纳米碳酸钙涂覆至聚丙烯隔膜表面,通过扫描电子显微镜、电化学测试、热稳定性分析等方法对改性后的隔膜进行了研究。结果表明,纳米碳酸钙质量分数为1.5%的改性隔膜孔隙率可达到46.47%±0.42%,电解液吸液率提升到168.03%±3.46%,改性后隔膜的电解液亲和性得到了改善。170℃时热收缩率为18.59%±4.12%,拉伸强度提升至169 MPa左右,隔膜的热稳定性与力学性能得到提升。改性后隔膜的离子电导率从0.50 m S/cm提升到了0.78 mS/cm,500次充放电循环后磷酸铁锂正极的放电比容量保持率为84.10%,并且在充放电循环过程中更加稳定。展开更多
基金financially supported by the National Key R&D Program of China(2023YFA1506602 and 2021YFA1501102)the National Natural Science Foundation of China(21932002,22276023,22402019)+1 种基金the Fundamental Research Funds for the Central Universities(DUT22LAB602)Liaoning Binhai Laboratory Project(LBLF-202306)。
文摘Cold plasma-assisted catalytic upcycling of polyolefin wastes integrated with CO_(2)into value-added chemicals is a promising solution for mitigating the global carbon emissions and fossil energy crisis,but still challenging due to the complexity of products and low energy efficiency.Given this,a novel one-stage process of cold plasma coupled with Ga-modified hierarchical H-ZSM-5(Ga/Hie-ZSM-5)catalyst for polyolefins upgrading was designed with polyolefins followed by the catalysts within the plasma region,which facilitated the upcycling of polyolefins to light olefins and CO_(2)activation by plasma,and thereby the enhanced synergy between cold plasma and catalysts for aromatics production.At an input power of ca.45 W without external heating,the low-density polyethylene(LDPE)waste was completely converted with the assistance of CO_(2)and the yield of oil products over the Ga/Hie-ZSM-5 catalyst was highly up to 62.2 wt%,with nearly 100% selectivity of aromatics.Meanwhile,the degradation efficiency of LDPE and the energy efficiency could reach 2.5 g_(LDPE)·g_(cat)^(-1)·h^(-1)and 55.56 g_(LDPE)·g_(cat)^(-1)·kW^(-1)h^(-1),respectively.Mechanism investigation revealed that the plasma and CO_(2)synergistically affect the primary cracking of LDPE,forming a primary product enriched in olefins and a small amount of CO.Subsequently,the produced olefins intermediates were further aromatized via cyclizationdehydrogenation route on the Ga/Hie-ZSM-5 catalyst with assistance of CO_(2)under the synergistic effect of plasma-catalysis.This work offers a feasible strategy to improve the yield of aromatic products for the plasma-catalytic upcycling of polyolefins and CO_(2)at ambient pressure without any external heating.
基金financially supported by the National Natural Science Foundation of China(No.52422301)Natural Science Foundation of Jilin Province(No.SKL202302033)。
文摘The crystallization behavior of two commercial polyolefin elastomer(POE)samples was investigated using the fast scanning chip calorimetry(FSC)technique.Non-isothermal crystallization of the POE samples during cooling to low temperatures cannot be inhibited under the largest efficient cooling rate employed in the current work.Thus,the isothermal crystallization of POE samples was limited to a narrow temperature range.When the POE samples were cooled to a certain temperature below the non-isothermal crystallization temperature for crystallization,a crystallization time dependent melting peak appeared in the low temperature region besides the high temperature melting peak originated from the non-isothermal crystallization.This low temperature melting peak was arisen from the melting of crystals isothermally crystallized at the selected crystallization temperature.At each crystallization temperature,the lengths of crystallizable segments were different,thus,the low melting peak increased with increasing the crystallization temperature.In terms of the high melting peak attributed to the non-isothermally crystallized crystals,it somehow decreased with increasing crystallization time and then became constant with further increasing crystallization time at the selected crystallization temperature.This could be explained by the fact that the crystallizable sequences with longer length would nucleate and crystallize first to form thicker crystals during cooling.The subsequent crystallization contributed by the shorter crystallizable sequences will result in the formation of thinner crystals,causing the melting peak to shift to the lower temperature.
文摘目前商用聚烯烃隔膜存在电解液亲和性和热稳定性差等问题,导致所组装电池的充放电性能和安全性有所欠缺。为改善电解液的亲和性及热稳定性,采用聚乙烯醇为黏结剂将纳米碳酸钙涂覆至聚丙烯隔膜表面,通过扫描电子显微镜、电化学测试、热稳定性分析等方法对改性后的隔膜进行了研究。结果表明,纳米碳酸钙质量分数为1.5%的改性隔膜孔隙率可达到46.47%±0.42%,电解液吸液率提升到168.03%±3.46%,改性后隔膜的电解液亲和性得到了改善。170℃时热收缩率为18.59%±4.12%,拉伸强度提升至169 MPa左右,隔膜的热稳定性与力学性能得到提升。改性后隔膜的离子电导率从0.50 m S/cm提升到了0.78 mS/cm,500次充放电循环后磷酸铁锂正极的放电比容量保持率为84.10%,并且在充放电循环过程中更加稳定。
