Pt3Co alloy nanoparticles were prepared by the reduction of H2PtCl6 and Co(OOCCH3)2 using NaBH4 as a reducing agent. The Pt3Co core-Pt shell nanoparticles (Pt3Co@Pt) were synthesized using hydrogen absorption reductio...Pt3Co alloy nanoparticles were prepared by the reduction of H2PtCl6 and Co(OOCCH3)2 using NaBH4 as a reducing agent. The Pt3Co core-Pt shell nanoparticles (Pt3Co@Pt) were synthesized using hydrogen absorption reduction and characterized by plasma-atomic emission spectrometry (ICP), transmission electron microscopy (TEM), X-ray diffraction (XRD) and SQUID magnetometer. The results show that average size of Pt3Co@Pt nanoparticles is 3.6 nm with a standard deviation of 0.9 nm. Heating Pt3Co nanoparticles in air at 700 ℃ for 1 h, Co in Pt3Co nanoparticles was oxidized to Co3O4 and CoO; while no oxidation tendency was detected for Pt3Co@Pt nanoparticles. The crystallize structure of Pt3Co@Pt changed from the face centered cube (fcc) to the face centered tetragonal (fct) after the heating treatment. The coercivity of the heated Pt3Co@Pt reached to 276 Oe at room temperature.展开更多
Directional design of efficient catalysts for volatile organic compounds degradation remains a complex,yet effective and challenging process.Herein,oxygen-rich vacancy Co_(3)O_(4)-anchored Pt catalysts were prepared t...Directional design of efficient catalysts for volatile organic compounds degradation remains a complex,yet effective and challenging process.Herein,oxygen-rich vacancy Co_(3)O_(4)-anchored Pt catalysts were prepared through atom-trapping strategy and relevant vacancy defect inductive effect was proposed.The 0.6Pt/VO-Co_(3)O_(4)catalyst presented a reaction rate value of 32.2×10^(-5)mol·g_(cat)^(-1)·s^(-1)at 160℃for catalytic propane total oxidation,which was nearly 5 times the reaction rate of Co_(3)O_(4)(6.7×10^(-5)mol·g_(cat)^(-1)·s^(-1)).Also,it exhibited excellent water-resistance and catalytic stability.The Pt atoms were stabilized on the Co_(3)O_(4)surface by vacancy defects to improve dispersion.Meanwhile,the vacancy defect inductive effect induced stronger electron interaction between Pt and Co_(3)O_(4)on the surface,thus promote the redox ability at low-temperature.The mobility and oxygen-activating ability of surface lattice oxygen were also strengthened by the vacancy defect inductive effect.This facilitated the generation of more surface-active oxygen species for the cleavage of C-H bond and the deep oxidation of intermediate species.Overall,this study proposed a novel concept the fabrication of highly efficient catalysts for the purpose of catalytic oxidation.展开更多
Traditional Pt/C electrode materials are prone to corrosion and detachment during H_(2)S detection,leading to a decrease in fuel cell-type sensor performance.Here,a high-performance H_(2)S sensor based on Pt loaded Ti...Traditional Pt/C electrode materials are prone to corrosion and detachment during H_(2)S detection,leading to a decrease in fuel cell-type sensor performance.Here,a high-performance H_(2)S sensor based on Pt loaded Ti_(3)C_(2)electrode material with-O/-OH terminal groups was designed and prepared.Experimental tests showed that the Pt/Ti_(3)C_(2)sensor has good sensitivity(0.162μA/ppm)and a very low detection limit to H_(2)S(10 ppb).After 90 days of stability testing,the response of the Pt/Ti_(3)C_(2)sensor shows a smaller decrease of 2%compared to that of the Pt/C sensor(22.9%).Meanwhile,the sensor also has high selectivity and repeatability.The density functional theory(DFT)calculation combined with the experiment results revealed that the improved H_(2)S sensing mechanism is attributed to the fact that the strong interaction between Pt and Ti_(3)C_(2)via the Pt-O-Ti bonding can reduce the formation energy of Pt and Ti_(3)C_(2),ultimately prolonging the sensor’s service life.Furthermore,the catalytic property of Pt can decrease the adsorption energy and dissociation barrier of H_(2)S on Pt/Ti_(3)C_(2)surface,greatly enhance the ability to generate protons and effectively transfer charges,realizing good sensitivity and high selectivity of the sensor.The sensor works at room temperature,making it very promising in the field of H_(2)S detection in future.展开更多
文摘Pt3Co alloy nanoparticles were prepared by the reduction of H2PtCl6 and Co(OOCCH3)2 using NaBH4 as a reducing agent. The Pt3Co core-Pt shell nanoparticles (Pt3Co@Pt) were synthesized using hydrogen absorption reduction and characterized by plasma-atomic emission spectrometry (ICP), transmission electron microscopy (TEM), X-ray diffraction (XRD) and SQUID magnetometer. The results show that average size of Pt3Co@Pt nanoparticles is 3.6 nm with a standard deviation of 0.9 nm. Heating Pt3Co nanoparticles in air at 700 ℃ for 1 h, Co in Pt3Co nanoparticles was oxidized to Co3O4 and CoO; while no oxidation tendency was detected for Pt3Co@Pt nanoparticles. The crystallize structure of Pt3Co@Pt changed from the face centered cube (fcc) to the face centered tetragonal (fct) after the heating treatment. The coercivity of the heated Pt3Co@Pt reached to 276 Oe at room temperature.
基金supported by the National Natural Science Foundation of China(21473155,21273198,21073159)the Natural Science Foundation of Zhejiang Province(L12B03001)~~
文摘Directional design of efficient catalysts for volatile organic compounds degradation remains a complex,yet effective and challenging process.Herein,oxygen-rich vacancy Co_(3)O_(4)-anchored Pt catalysts were prepared through atom-trapping strategy and relevant vacancy defect inductive effect was proposed.The 0.6Pt/VO-Co_(3)O_(4)catalyst presented a reaction rate value of 32.2×10^(-5)mol·g_(cat)^(-1)·s^(-1)at 160℃for catalytic propane total oxidation,which was nearly 5 times the reaction rate of Co_(3)O_(4)(6.7×10^(-5)mol·g_(cat)^(-1)·s^(-1)).Also,it exhibited excellent water-resistance and catalytic stability.The Pt atoms were stabilized on the Co_(3)O_(4)surface by vacancy defects to improve dispersion.Meanwhile,the vacancy defect inductive effect induced stronger electron interaction between Pt and Co_(3)O_(4)on the surface,thus promote the redox ability at low-temperature.The mobility and oxygen-activating ability of surface lattice oxygen were also strengthened by the vacancy defect inductive effect.This facilitated the generation of more surface-active oxygen species for the cleavage of C-H bond and the deep oxidation of intermediate species.Overall,this study proposed a novel concept the fabrication of highly efficient catalysts for the purpose of catalytic oxidation.
基金the National Key R&D Program of China(No.2023YFB3210102).
文摘Traditional Pt/C electrode materials are prone to corrosion and detachment during H_(2)S detection,leading to a decrease in fuel cell-type sensor performance.Here,a high-performance H_(2)S sensor based on Pt loaded Ti_(3)C_(2)electrode material with-O/-OH terminal groups was designed and prepared.Experimental tests showed that the Pt/Ti_(3)C_(2)sensor has good sensitivity(0.162μA/ppm)and a very low detection limit to H_(2)S(10 ppb).After 90 days of stability testing,the response of the Pt/Ti_(3)C_(2)sensor shows a smaller decrease of 2%compared to that of the Pt/C sensor(22.9%).Meanwhile,the sensor also has high selectivity and repeatability.The density functional theory(DFT)calculation combined with the experiment results revealed that the improved H_(2)S sensing mechanism is attributed to the fact that the strong interaction between Pt and Ti_(3)C_(2)via the Pt-O-Ti bonding can reduce the formation energy of Pt and Ti_(3)C_(2),ultimately prolonging the sensor’s service life.Furthermore,the catalytic property of Pt can decrease the adsorption energy and dissociation barrier of H_(2)S on Pt/Ti_(3)C_(2)surface,greatly enhance the ability to generate protons and effectively transfer charges,realizing good sensitivity and high selectivity of the sensor.The sensor works at room temperature,making it very promising in the field of H_(2)S detection in future.
