A series of Co-Ni_2P/SBA-15 catalysts with various Co contents, Ni_2P contents and P/Ni molar ratios were prepared by impregnating nickel nitrate, diammonium hydrogen phosphate, and then cobalt nitrate into SBA-15 sup...A series of Co-Ni_2P/SBA-15 catalysts with various Co contents, Ni_2P contents and P/Ni molar ratios were prepared by impregnating nickel nitrate, diammonium hydrogen phosphate, and then cobalt nitrate into SBA-15 support followed by temperature-programmed reduction in a H_2 flow. The catalyst structure was characterized by X-ray diffraction （XRD）, high resolution-transmission electron microscopy （HR-TEM） and N_2 adsorption-desorption techniques and their catalytic performance of the hydrodesulfurization （HDS） of dibenzothiophene （DBT） was evaluated. The effects of Co contents, Ni_2P contents and P/Ni molar ratios on the catalyst structure and HDS of DBT over the Co-Ni_2P/SBA- 15 catalyst were investigated. The results indicated that the mesoporous structure was mainly maintained and the nickel phosphides were well dispersed in all of the characterized catalysts. The 4Co-25Ni_2P/SBA-15 （P/Ni = 0.8） catalyst with the Co and Ni_2P contents of 4 wt% and 25 wt%, respectively, and the P/Ni molar ratio of 0.8 showed the highest catalytic performance for HDS of DBT. Under the reaction conditions of 380 ℃ and 3.0 MPa, the DBT conversion can reach 99.62%. The HDS of DBT proceeded mainly via the direct desulfurization （DDS） pathway with biphenyl （BP） as the dominant product on all of the catalysts and the BP selectivity was slightly enhanced after the introduction of Co promoters.展开更多
Although electrocatalytic water splitting holds significant promise for hydrogen production,unfavorable reaction energy barriers and kinetic properties lead to unsatisfactory conversion efficiency.Herein,we provide an...Although electrocatalytic water splitting holds significant promise for hydrogen production,unfavorable reaction energy barriers and kinetic properties lead to unsatisfactory conversion efficiency.Herein,we provide an innovative strategy to optimize the electrochemical activity of the Fe/Ni_(2)P catalyst through near-infrared(NIR)-induced photothermal effect.The Fe/Ni_(2)P-NIR yields a current density of 10 mA cm^(-2)at ultralow overpotentials of 16 mV for the hydrogen evolution reaction(HER)and 167 mV for the oxygen evolution reaction(OER),with Tafel slopes of 38.7 and 46.2 mV dec^(-1),respectively.This bifunctional catalyst also delivers 10 mA cm^(-2)at a low voltage of 1.40 V for overall water splitting.The NIR photoinduced local thermal effect activates abundant catalytic sites,accelerates charge and mass transfer,and improves intrinsic reaction kinetics.Guided by density functional theory(DFT)calculations,the photothermal effect reduces the energy barriers of the rate-determining steps(RDS)for^(*)H desorption on Fe/Ni_(2)P during HER and^(*)O formation on its reconstructed active phase NiFeOOH during OER.We realized photothermal-electrochemical integration with Fe/Ni_(2)P-NIR in an anion exchange membrane(AEM)electrolyzer,attaining 500 mA cm^(-2)at 1.76 V,with excellent stability over 50 h.This strategy may significantly advance energy conversion technology towards economic hydrogen production through water electrolysis.展开更多
Highly active and low-cost catalytic electrodes for urea oxidation reaction(UOR)are always crucial for exploration of urea fuel cells.Herein,novel york-shell-structural Ni_(2)P/C na nosphere hybrids(Ni_(2)P/C-YS)are r...Highly active and low-cost catalytic electrodes for urea oxidation reaction(UOR)are always crucial for exploration of urea fuel cells.Herein,novel york-shell-structural Ni_(2)P/C na nosphere hybrids(Ni_(2)P/C-YS)are rationally constructed via a hydrothermal method and subsequent phosphidation treatment under different temperature ranging from 250℃to 450℃for UOR applications.In the in-situ constructed hollow york-shell structure,the coupling of conductive carbon materials and active Ni_(2)P allows numerous interfaces facilitating the electron transfer and thereby accelerating the catalytic kinetics.The results demonstrate that Ni_(2)P/C-YS-350 nanocomposite can boost the UOR process with a low potential of 1.366 V vs.RHE at a current density of 50 mA/cm^(2) in alkaline electrolyte and afford the superior durability with negligible potential decay after 23 h.This study presents that the carbon coated Ni_(2)P hybrid with the optimized crystallinities and hollow york-shell configurations can be a promising candidate for application in urea fuel cells.展开更多
基金supported by the National Basic Research Program of China(2006CB202503)Petro China Innovation Foundation(2010D-5006-0401)
文摘A series of Co-Ni_2P/SBA-15 catalysts with various Co contents, Ni_2P contents and P/Ni molar ratios were prepared by impregnating nickel nitrate, diammonium hydrogen phosphate, and then cobalt nitrate into SBA-15 support followed by temperature-programmed reduction in a H_2 flow. The catalyst structure was characterized by X-ray diffraction （XRD）, high resolution-transmission electron microscopy （HR-TEM） and N_2 adsorption-desorption techniques and their catalytic performance of the hydrodesulfurization （HDS） of dibenzothiophene （DBT） was evaluated. The effects of Co contents, Ni_2P contents and P/Ni molar ratios on the catalyst structure and HDS of DBT over the Co-Ni_2P/SBA- 15 catalyst were investigated. The results indicated that the mesoporous structure was mainly maintained and the nickel phosphides were well dispersed in all of the characterized catalysts. The 4Co-25Ni_2P/SBA-15 （P/Ni = 0.8） catalyst with the Co and Ni_2P contents of 4 wt% and 25 wt%, respectively, and the P/Ni molar ratio of 0.8 showed the highest catalytic performance for HDS of DBT. Under the reaction conditions of 380 ℃ and 3.0 MPa, the DBT conversion can reach 99.62%. The HDS of DBT proceeded mainly via the direct desulfurization （DDS） pathway with biphenyl （BP） as the dominant product on all of the catalysts and the BP selectivity was slightly enhanced after the introduction of Co promoters.
基金the support from the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.52488201)the National Key R&D Program of China(2021YFF0500504)the Fundamental Research Funds for the Central Universities。
文摘Although electrocatalytic water splitting holds significant promise for hydrogen production,unfavorable reaction energy barriers and kinetic properties lead to unsatisfactory conversion efficiency.Herein,we provide an innovative strategy to optimize the electrochemical activity of the Fe/Ni_(2)P catalyst through near-infrared(NIR)-induced photothermal effect.The Fe/Ni_(2)P-NIR yields a current density of 10 mA cm^(-2)at ultralow overpotentials of 16 mV for the hydrogen evolution reaction(HER)and 167 mV for the oxygen evolution reaction(OER),with Tafel slopes of 38.7 and 46.2 mV dec^(-1),respectively.This bifunctional catalyst also delivers 10 mA cm^(-2)at a low voltage of 1.40 V for overall water splitting.The NIR photoinduced local thermal effect activates abundant catalytic sites,accelerates charge and mass transfer,and improves intrinsic reaction kinetics.Guided by density functional theory(DFT)calculations,the photothermal effect reduces the energy barriers of the rate-determining steps(RDS)for^(*)H desorption on Fe/Ni_(2)P during HER and^(*)O formation on its reconstructed active phase NiFeOOH during OER.We realized photothermal-electrochemical integration with Fe/Ni_(2)P-NIR in an anion exchange membrane(AEM)electrolyzer,attaining 500 mA cm^(-2)at 1.76 V,with excellent stability over 50 h.This strategy may significantly advance energy conversion technology towards economic hydrogen production through water electrolysis.
基金financially supported by the National Key Research and Development Program of China(No.2017YFE0120500)the National Natural Science Foundation of China(Nos.51804223 and 51972129)+4 种基金CAS Key Laboratory of Nano-Bio Interface(No.19ZY01)the South Xinjiang Innovation and Development Program of Key Industries of Xinjiang Production and Construction Corps(No.2020DB002)the Scientific Research Foundation of Wuhan Institute of Technology(No.K201761)the Fundamental Research Funds for the Central Universities(Nos.HUST 2018KFYYXJJ051,2019KFYXMBZ076)the Hubei"Chu-Tian Young Scholar"Program。
文摘Highly active and low-cost catalytic electrodes for urea oxidation reaction(UOR)are always crucial for exploration of urea fuel cells.Herein,novel york-shell-structural Ni_(2)P/C na nosphere hybrids(Ni_(2)P/C-YS)are rationally constructed via a hydrothermal method and subsequent phosphidation treatment under different temperature ranging from 250℃to 450℃for UOR applications.In the in-situ constructed hollow york-shell structure,the coupling of conductive carbon materials and active Ni_(2)P allows numerous interfaces facilitating the electron transfer and thereby accelerating the catalytic kinetics.The results demonstrate that Ni_(2)P/C-YS-350 nanocomposite can boost the UOR process with a low potential of 1.366 V vs.RHE at a current density of 50 mA/cm^(2) in alkaline electrolyte and afford the superior durability with negligible potential decay after 23 h.This study presents that the carbon coated Ni_(2)P hybrid with the optimized crystallinities and hollow york-shell configurations can be a promising candidate for application in urea fuel cells.
