Polyvinyl chloride is the most widely used general-purpose plastic and plays a vital role in various industries.Mercury-based catalysts severely limit the green sustainability of industry.Non-metallic carbon materials...Polyvinyl chloride is the most widely used general-purpose plastic and plays a vital role in various industries.Mercury-based catalysts severely limit the green sustainability of industry.Non-metallic carbon materials are very promising alternatives in acetylene hydrochlorination,but their stability remains a challenge of major concern at present.Based on the principle of green chemistry,structurally tunable and defect-rich carbon materials were synthesized by hydrothermal carbonization and pyrolysis using glucose as carbon source and m-phenylenediamine as nitrogen source and cross-linking agent.Experimental characterization and density functional theory confirmed that pyridinic N was the main active site.The introduction of N not only regulated the formation of the hierarchically porous structure of the carbon material,but also increased the adsorption of HCl and decreased the adsorption strength of C_(2)H_(2).The synergistic effect of high N content and porous structure significantly enhanced the catalytic performance of the catalysts in acetylene hydrochlorination.The C_(2)H_(2)conversion was maintained at around98%after 100 h under the reaction conditions(T=220°C,GHSV(C_(2)H_(2))=30 h^(-1),V_(HCl)/VC_(2)H_(2)=1.15).Thus,the one-pot synthesis process used here is a good benchmark for future catalyst research.展开更多
Lithium–sulfur(Li–S)battery is attracting increasing interest for its potential in low-cost high-density energy storage.However,it has been a persistent challenge to simultaneously realize high energy density and lo...Lithium–sulfur(Li–S)battery is attracting increasing interest for its potential in low-cost high-density energy storage.However,it has been a persistent challenge to simultaneously realize high energy density and long cycle life.Herein,we report a synergistic strategy to exploit a unique nitrogen-doped three-dimensional graphene aerogel as both the lithium anode host to ensure homogeneous lithium plating/stripping and mitigate lithium dendrite formation and the sulfur cathode host to facilitate efficient sulfur redox chemistry and combat undesirable polysulfide shuttling effect,realizing Li–S battery simultaneously with ultrahigh energy density and long cycle life.The as-demonstrated polysulfide-based device delivers a high areal capacity of 7.5 mAh/cm^(2)(corresponds to 787 Wh/L)and an ultralow capacity fading of 0.025%per cycle over 1000 cycles at a high current density of 8.6 mA/cm^(2).Our findings suggest a novel strategy to scale up the superior electrochemical property of every microscopic unit to a macroscopic-level performance that enables simultaneously high areal energy density and long cycling stability that are critical for practical Li–S batteries.展开更多
基金supported by the Tianchi Innovation Leading Talent Development Fund(No.CZ002710)in Xinjiangthe Taishan Scholars Program of Shandong Province(No.tsqn202103051)+4 种基金the Project of Science and Technology Development of Yantai City(No.2023JCYJ073)Natural science foundation of Shandong province(No.ZR2023MB064)special funds for over provincial level leading talent of Yantai citythe Start-Up Foundation for High-level Professionals of Shihezi University(No.RCZK201932)Tianshan Talents Training Program of Xinjiang(Science and Technology Innovation Team,No.2022TSYCTD0021)。
文摘Polyvinyl chloride is the most widely used general-purpose plastic and plays a vital role in various industries.Mercury-based catalysts severely limit the green sustainability of industry.Non-metallic carbon materials are very promising alternatives in acetylene hydrochlorination,but their stability remains a challenge of major concern at present.Based on the principle of green chemistry,structurally tunable and defect-rich carbon materials were synthesized by hydrothermal carbonization and pyrolysis using glucose as carbon source and m-phenylenediamine as nitrogen source and cross-linking agent.Experimental characterization and density functional theory confirmed that pyridinic N was the main active site.The introduction of N not only regulated the formation of the hierarchically porous structure of the carbon material,but also increased the adsorption of HCl and decreased the adsorption strength of C_(2)H_(2).The synergistic effect of high N content and porous structure significantly enhanced the catalytic performance of the catalysts in acetylene hydrochlorination.The C_(2)H_(2)conversion was maintained at around98%after 100 h under the reaction conditions(T=220°C,GHSV(C_(2)H_(2))=30 h^(-1),V_(HCl)/VC_(2)H_(2)=1.15).Thus,the one-pot synthesis process used here is a good benchmark for future catalyst research.
基金This work was financially supported by Scientific ResearchStart-up Funds of Tsinghua SIGS(Grant NumberQD2021018C to L.P.)the National Natural Science Founda-tion of China(Grant Numbers 20231710015 , 22209096 to L.P.)+2 种基金GuangDong Basic and Applied Basic ResearchFoundation(No.2023A1515010059 to L.P.)ShenzhenFundamental Research Program(No.JCYJ20220530143003008 to L.P.)C.Z.acknowledges the financial supportfrom the National Natural Science Foundation of China(Grant Number 51472031)
文摘Lithium–sulfur(Li–S)battery is attracting increasing interest for its potential in low-cost high-density energy storage.However,it has been a persistent challenge to simultaneously realize high energy density and long cycle life.Herein,we report a synergistic strategy to exploit a unique nitrogen-doped three-dimensional graphene aerogel as both the lithium anode host to ensure homogeneous lithium plating/stripping and mitigate lithium dendrite formation and the sulfur cathode host to facilitate efficient sulfur redox chemistry and combat undesirable polysulfide shuttling effect,realizing Li–S battery simultaneously with ultrahigh energy density and long cycle life.The as-demonstrated polysulfide-based device delivers a high areal capacity of 7.5 mAh/cm^(2)(corresponds to 787 Wh/L)and an ultralow capacity fading of 0.025%per cycle over 1000 cycles at a high current density of 8.6 mA/cm^(2).Our findings suggest a novel strategy to scale up the superior electrochemical property of every microscopic unit to a macroscopic-level performance that enables simultaneously high areal energy density and long cycling stability that are critical for practical Li–S batteries.
