Electrochemical alcohol oxidation,the alternate of oxygen evolution reaction,has been recognized as an effective way to produce value-added chemicals coupled with H2 production.However,the current researches still suf...Electrochemical alcohol oxidation,the alternate of oxygen evolution reaction,has been recognized as an effective way to produce value-added chemicals coupled with H2 production.However,the current researches still suffer from the low reaction rate and Faradaic efficiency(FE)that limits the overall efficiency.Herein,we report a ligand intercalation strategy to enhance the current density of alcohol electrooxidation by intercalating sodium dodecyl sulfonate(SDS)in the interlayer of Co(OH)_(2)catalyst(Co(OH)_(2)-SDS).For instance,the Co(OH)_(2)-SDS shows obviously enhanced current density for glycerol electrooxidation than that of pure Co(OH)_(2).The corresponding glycerol conversion rate and H2 production rate reach 0.35 mmol·cm^(−2)·h^(−1)and 9.1 mL·cm^(−2)·h^(−1)at 1.42 V vs.reversible hydrogen electrode,which are 2.2-and 1.9-fold higher than that of Co(OH)_(2).The yield of formate reaches 86.6%with selectivity of 95.3%at high glycerol conversion of 95.1%(with FE of 83.3%for glycerol oxidation).The Co(OH)_(2)-SDS is demonstrated efficient for different alcohols with enhanced performance.We confirmed that the intercalation of SDS in Co(OH)_(2)can promote the generation and exposure of CoOOH reactive sites,and also facilitate the adsorption of alcohol,thus enabling high reaction rate.展开更多
Chemical oxidation and metal intercalation of natural graphite was utilized to increase the capacity and enhance the cycle property of graphite anodes in lithium ion batteries.
Graphene layers are often exposed to gaseous environments in their synthesis and application processes, and interactions of graphene surfaces with molecules particularly H2 and O2 are of great importance in their phys...Graphene layers are often exposed to gaseous environments in their synthesis and application processes, and interactions of graphene surfaces with molecules particularly H2 and O2 are of great importance in their physico-chemical properties. In this work, etching of graphene overlayers on Pt（111） in H2 and O2 atmospheres were investigated by in-situ low energy electron microscopy. Significant graphene etching was observed in 10-5 Torr H2 above 1O23 K, which occurs simultaneously at graphene island edges and interiors with a determined reaction barrier at 5.7 eV. The similar etching phenomena were found in 10 7 Torr O2 above 973 K, while only island edges were reacted between 823 and 923 K. We suggest that etching of graphene edges is facilitated by Pt-aided hydrogenation or oxidation of edge carbon atoms while intercalation-etching is attributed to etching at the interiors at high temperatures. The different findings with etching in O2 and H2 depend on competitive adsorption, desorption, and diffusion processes of O and H atoms on Pt surface, as well as intercalation at the graphene/Pt interface.展开更多
本文以50目天然鳞片石墨为原料,K2Cr2O7为氧化剂,采用化学氧化法制备可膨胀石墨,并研究了各种反应条件对膨胀体积的影响。结果表明:硫酸做插层剂时膨胀效果较好;室温下,石墨与硫酸、重铬酸钾配比为1︰3︰0.15,反应时间为120 min时,可膨...本文以50目天然鳞片石墨为原料,K2Cr2O7为氧化剂,采用化学氧化法制备可膨胀石墨,并研究了各种反应条件对膨胀体积的影响。结果表明:硫酸做插层剂时膨胀效果较好;室温下,石墨与硫酸、重铬酸钾配比为1︰3︰0.15,反应时间为120 min时,可膨胀石墨的膨胀体积可达260 m L/g。展开更多
Using Mn(OH)2 as precursor, LiOH as lithiat- ing agent and (NH4)2S2O8 as oxidant, layered o-LiMnO2 was obtained by a novel method——in situ oxidation-intercalation under mild conditions (80℃). The product was charac...Using Mn(OH)2 as precursor, LiOH as lithiat- ing agent and (NH4)2S2O8 as oxidant, layered o-LiMnO2 was obtained by a novel method——in situ oxidation-intercalation under mild conditions (80℃). The product was characterized by XRD, ICP, TEM and Li-NMR. The results reveal that 7 orthorhombic LiMnO2 with high purity and good crystallin- ity can be obtained by this method. During electrochemical tests, a LiMnO2/Li cell shows an initial reversible capacity of 208 mAh·g?1 and a reversible capacity of 180 mAh·g?1 after 30 cycles at room temperature.展开更多
基金supported by the National Natural Science Foundation of China(No.22105026)the Science and Technology Project of Beijing Education Commission(No.KM202110017004),the Natural Science Foundation of Beijing Municipality(No.2184102)+1 种基金the Beijing Talent Training Foundation(No.2017000020124G082)the URT Program of Beijing Institute of Petrochemical Technology(Nos.2022J00053 and 2021J00106).
文摘Electrochemical alcohol oxidation,the alternate of oxygen evolution reaction,has been recognized as an effective way to produce value-added chemicals coupled with H2 production.However,the current researches still suffer from the low reaction rate and Faradaic efficiency(FE)that limits the overall efficiency.Herein,we report a ligand intercalation strategy to enhance the current density of alcohol electrooxidation by intercalating sodium dodecyl sulfonate(SDS)in the interlayer of Co(OH)_(2)catalyst(Co(OH)_(2)-SDS).For instance,the Co(OH)_(2)-SDS shows obviously enhanced current density for glycerol electrooxidation than that of pure Co(OH)_(2).The corresponding glycerol conversion rate and H2 production rate reach 0.35 mmol·cm^(−2)·h^(−1)and 9.1 mL·cm^(−2)·h^(−1)at 1.42 V vs.reversible hydrogen electrode,which are 2.2-and 1.9-fold higher than that of Co(OH)_(2).The yield of formate reaches 86.6%with selectivity of 95.3%at high glycerol conversion of 95.1%(with FE of 83.3%for glycerol oxidation).The Co(OH)_(2)-SDS is demonstrated efficient for different alcohols with enhanced performance.We confirmed that the intercalation of SDS in Co(OH)_(2)can promote the generation and exposure of CoOOH reactive sites,and also facilitate the adsorption of alcohol,thus enabling high reaction rate.
文摘Chemical oxidation and metal intercalation of natural graphite was utilized to increase the capacity and enhance the cycle property of graphite anodes in lithium ion batteries.
基金supported by the National Natural Science Foundation of China(21373208,21688102,91545204,21621063)Ministry of Science and Technology of China(2016YFA0200200,2013CB834603,2013CB933100)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020200)
文摘Graphene layers are often exposed to gaseous environments in their synthesis and application processes, and interactions of graphene surfaces with molecules particularly H2 and O2 are of great importance in their physico-chemical properties. In this work, etching of graphene overlayers on Pt（111） in H2 and O2 atmospheres were investigated by in-situ low energy electron microscopy. Significant graphene etching was observed in 10-5 Torr H2 above 1O23 K, which occurs simultaneously at graphene island edges and interiors with a determined reaction barrier at 5.7 eV. The similar etching phenomena were found in 10 7 Torr O2 above 973 K, while only island edges were reacted between 823 and 923 K. We suggest that etching of graphene edges is facilitated by Pt-aided hydrogenation or oxidation of edge carbon atoms while intercalation-etching is attributed to etching at the interiors at high temperatures. The different findings with etching in O2 and H2 depend on competitive adsorption, desorption, and diffusion processes of O and H atoms on Pt surface, as well as intercalation at the graphene/Pt interface.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20301002)Beijing Nova Fund(Grant No.H013610350112).
文摘Using Mn(OH)2 as precursor, LiOH as lithiat- ing agent and (NH4)2S2O8 as oxidant, layered o-LiMnO2 was obtained by a novel method——in situ oxidation-intercalation under mild conditions (80℃). The product was characterized by XRD, ICP, TEM and Li-NMR. The results reveal that 7 orthorhombic LiMnO2 with high purity and good crystallin- ity can be obtained by this method. During electrochemical tests, a LiMnO2/Li cell shows an initial reversible capacity of 208 mAh·g?1 and a reversible capacity of 180 mAh·g?1 after 30 cycles at room temperature.
