The timely and effective detection of CO and CH_(4) is critical as the explosion and poisoning of them can bring serious potential risks to coal mining.In this study,combining metal oxide semiconductors with noble met...The timely and effective detection of CO and CH_(4) is critical as the explosion and poisoning of them can bring serious potential risks to coal mining.In this study,combining metal oxide semiconductors with noble metals offers a promising route to achieve this target.Hierarchical porous Pd modified In_(2)O_(3) nanoflowers were prepared via two-step hydrothermal method and exhibited dual detection of CO and CH_(4) at different temperatures.The material has been characterized by a number of advanced techniques and the results indicate that Pd modified In_(2)O_(3) are hierarchical porous nanoflowers structure consisting of pores of approximately 1.8 nm in size.The sensing properties results show that the Pd modified In_(2)O_(3) based sensor exhibits temperature-dependent dual selectivity detection of CO at 280℃ and CH_(4) at 340℃.In addition,the Pd modified In_(2)O_(3) sensor display higher sensing response of CO(5.824 for 100 ppm)and CH_(4)(1.162 for 1000 ppm),fast response and recovery time,as well as good repeatability,which demonstrating the great potential for practical application.Such good gas-sensing performance are mainly attributed to the unique flower-like structure,the presence of porosity on the sample surface,and the catalytic effect of Pd.展开更多
Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinet...Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinetics of divalent charge Zn^(2+)in the cathode materials caused by the strong electrostatic interaction and their unsatisfactory cycle life hinder the development of ZIBs.Herein,organic cations and Zn^(2+)ions co-pre-inserted vanadium oxide([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O are reported as the cathode for ultra-stable aqueous ZIBs,in which the weaker electrostatic interactions between Zn^(2+)and organic ion-pinned vanadium oxide can induce the high reversibility of Zn^(2+)insertion and extraction,thereby improving the cycle life.It is demonstrated that([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O cathodes deliver a discharge capacity of 181 mA h g^(-1)at8 A g^(-1)and ultra-long life span(99.5%capacity retention after 2000 cycles).A reversible Zn^(2+)/H^(+)ions(de)intercalation storage process and pseudocapacitive charge storage are characterized.The weaker interactions between organic ion and Zn^(2+)open a novel avenue for the design of highly reversible cathode materials with long-term cycling stability.展开更多
Co_(3)O_(4)-SnO_(2)hybrid oxides were prepared by the coprecipitation method and were used to oxidate methane(CH4)in presence of oxygen.The Co_(3)O_(4)-SnO_(2)with a molar ratio of Co/(Co+Sn)at 0.75 exhibited the high...Co_(3)O_(4)-SnO_(2)hybrid oxides were prepared by the coprecipitation method and were used to oxidate methane(CH4)in presence of oxygen.The Co_(3)O_(4)-SnO_(2)with a molar ratio of Co/(Co+Sn)at 0.75 exhibited the highest catalytic activity among all the Co_(3)O_(4)-SnO_(2)hybrid oxides.Experimental results showed that the catalysts were considerably stable in the CH4 combustion reaction,and were verified by X-ray photoelectron spectra(XPS).It was found that Co_(3)O_(4)was the active species,and SnO_(2)acted as a support or a promoting component in the Co_(3)O_(4)-SnO_(2)hybrid oxides.The surface area was not a major factor that affected catalytic activity.The hydrogen temperatureprogrammed reduction(H_(2)-TPR)results demonstrated that the interaction between cobalt and tin oxides accelerated the mobility of oxygen species of Co_(3)O_(4)-SnO_(2),leading to higher catalytic activity.展开更多
A Pt-Rh three-way catalyst（M-DS） supported on CeO_2-ZrO_2-La_2O_3-Nd_2O_3 and its analogous supported catalyst（DS） were developed via a modified double-solvent method and conventional double-solvent method, respec...A Pt-Rh three-way catalyst（M-DS） supported on CeO_2-ZrO_2-La_2O_3-Nd_2O_3 and its analogous supported catalyst（DS） were developed via a modified double-solvent method and conventional double-solvent method, respectively. The as-prepared catalysts were characterized by N_2 adsorption-desorption, X-ray diffraction（XRD）, CO-chemisorption, X-ray photoelectron spectroscopy（XPS） and hydrogen temperature-programmed reduction（H_2-TPR）. The preformed Pt nanoparticles generated using ethanol as a reducing agent on M-DS presented enhanced Pt dispersion regardless of aging treatment as confirmed by XRD and CO-chemisorption measurements. The textural properties and reduction ability of M-DS were maintained to a large extent after aging treatment. This result was consistent with those of the N_2 adsorption-desorption and H_2-TPR, respectively. Meanwhile, the XPS analysis demonstrated that higher Pt^0 species and larger Ce^（3＋） concentration could be obtained for M-DS. In the conversion of a simulated compressed natural gas（CNG） vehicle exhaust, both fresh and aged M-DS showed a significant enhancement in the activity and N_2-selectivity. Particularly, the complete conversion temperature（T_（90）） of CH_4 over the aged M-DS catalyst was 65 oC lower than that over the aged catalyst by conventional double-solvent method.展开更多
基金This work is supported by the National Natural Science Foundation of China(U1704255,62101177)the fellowship of China Postdoctoral Science Foundation(2021M690919)+1 种基金Youth Project of Natural Science Foundation of Henan Province(212300410149)the Key Scientific Research Project of Colleges and University in Henan Province(21A430019).
文摘The timely and effective detection of CO and CH_(4) is critical as the explosion and poisoning of them can bring serious potential risks to coal mining.In this study,combining metal oxide semiconductors with noble metals offers a promising route to achieve this target.Hierarchical porous Pd modified In_(2)O_(3) nanoflowers were prepared via two-step hydrothermal method and exhibited dual detection of CO and CH_(4) at different temperatures.The material has been characterized by a number of advanced techniques and the results indicate that Pd modified In_(2)O_(3) are hierarchical porous nanoflowers structure consisting of pores of approximately 1.8 nm in size.The sensing properties results show that the Pd modified In_(2)O_(3) based sensor exhibits temperature-dependent dual selectivity detection of CO at 280℃ and CH_(4) at 340℃.In addition,the Pd modified In_(2)O_(3) sensor display higher sensing response of CO(5.824 for 100 ppm)and CH_(4)(1.162 for 1000 ppm),fast response and recovery time,as well as good repeatability,which demonstrating the great potential for practical application.Such good gas-sensing performance are mainly attributed to the unique flower-like structure,the presence of porosity on the sample surface,and the catalytic effect of Pd.
基金supported by the funding from the National Natural Science Foundation of China(grant nos.51902187,52072224,and 51732007)the Natural Science Foundation of Shandong Province(ZR2018BEM010)+3 种基金the Science Fund for Distinguished Young Scholars of Shandong Province(ZR2019JQ16)the Fundamental Research Funds of Shandong UniversityYoung Elite Scientist Sponsorship Program by CAST(YESS)the support from Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong
文摘Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinetics of divalent charge Zn^(2+)in the cathode materials caused by the strong electrostatic interaction and their unsatisfactory cycle life hinder the development of ZIBs.Herein,organic cations and Zn^(2+)ions co-pre-inserted vanadium oxide([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O are reported as the cathode for ultra-stable aqueous ZIBs,in which the weaker electrostatic interactions between Zn^(2+)and organic ion-pinned vanadium oxide can induce the high reversibility of Zn^(2+)insertion and extraction,thereby improving the cycle life.It is demonstrated that([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O cathodes deliver a discharge capacity of 181 mA h g^(-1)at8 A g^(-1)and ultra-long life span(99.5%capacity retention after 2000 cycles).A reversible Zn^(2+)/H^(+)ions(de)intercalation storage process and pseudocapacitive charge storage are characterized.The weaker interactions between organic ion and Zn^(2+)open a novel avenue for the design of highly reversible cathode materials with long-term cycling stability.
基金the National Natural Science Foundation of China(Grant No.20677034 and 20707012)the National High-Tech Research and Development Program(863 program)of China(Grant No.2006AA060301).
文摘Co_(3)O_(4)-SnO_(2)hybrid oxides were prepared by the coprecipitation method and were used to oxidate methane(CH4)in presence of oxygen.The Co_(3)O_(4)-SnO_(2)with a molar ratio of Co/(Co+Sn)at 0.75 exhibited the highest catalytic activity among all the Co_(3)O_(4)-SnO_(2)hybrid oxides.Experimental results showed that the catalysts were considerably stable in the CH4 combustion reaction,and were verified by X-ray photoelectron spectra(XPS).It was found that Co_(3)O_(4)was the active species,and SnO_(2)acted as a support or a promoting component in the Co_(3)O_(4)-SnO_(2)hybrid oxides.The surface area was not a major factor that affected catalytic activity.The hydrogen temperatureprogrammed reduction(H_(2)-TPR)results demonstrated that the interaction between cobalt and tin oxides accelerated the mobility of oxygen species of Co_(3)O_(4)-SnO_(2),leading to higher catalytic activity.
基金supported by the National Key Research and Development Program of China(2016YFC0204902)
文摘A Pt-Rh three-way catalyst（M-DS） supported on CeO_2-ZrO_2-La_2O_3-Nd_2O_3 and its analogous supported catalyst（DS） were developed via a modified double-solvent method and conventional double-solvent method, respectively. The as-prepared catalysts were characterized by N_2 adsorption-desorption, X-ray diffraction（XRD）, CO-chemisorption, X-ray photoelectron spectroscopy（XPS） and hydrogen temperature-programmed reduction（H_2-TPR）. The preformed Pt nanoparticles generated using ethanol as a reducing agent on M-DS presented enhanced Pt dispersion regardless of aging treatment as confirmed by XRD and CO-chemisorption measurements. The textural properties and reduction ability of M-DS were maintained to a large extent after aging treatment. This result was consistent with those of the N_2 adsorption-desorption and H_2-TPR, respectively. Meanwhile, the XPS analysis demonstrated that higher Pt^0 species and larger Ce^（3＋） concentration could be obtained for M-DS. In the conversion of a simulated compressed natural gas（CNG） vehicle exhaust, both fresh and aged M-DS showed a significant enhancement in the activity and N_2-selectivity. Particularly, the complete conversion temperature（T_（90）） of CH_4 over the aged M-DS catalyst was 65 oC lower than that over the aged catalyst by conventional double-solvent method.
