The catalytic performance of supported metal catalysts is highly dependent on the interfacial contact between the metal centers and support materials,which could dynamically adapt to the chemical environment in the re...The catalytic performance of supported metal catalysts is highly dependent on the interfacial contact between the metal centers and support materials,which could dynamically adapt to the chemical environment in the reactions.Herein,the well-known Ru/TiO_(x)interface of the Ru/TiO_(2)catalyst is shown to be transformed into Ru/TiO_(x)N_(y)during the NH_(3)decomposition,which is derived from the nitridation of the support by N^(*)species.Through a series of characterizations and density functional theory(DFT)calculations,it is found that such a nitrogenous interface primarily blocks the cleavage of N-H bonds with a higher energy barrier,leading to the deactivation of Ru/TiO_(2)in NH_(3)decomposition.Nevertheless,the Ru/TiO_(x)interface can be easily restored by oxidation and a subsequent H2 reduction,contributing to the recovery of the catalytic activity toward NH_(3)decomposition.Our study provides a new insight into the deactivation mechanism of Ru/TiO_(2)in NH_(3)decomposition and highlights the significance of the dynamic evolution of the metal-support interfaces in the reactions.展开更多
Synthesis of spherical carbon beads with effective CO_2 capture capability is highly desirable for large scale application of CO2 sorption, but remains challenging. Herein, a facile and efficient strategy to prepare n...Synthesis of spherical carbon beads with effective CO_2 capture capability is highly desirable for large scale application of CO2 sorption, but remains challenging. Herein, a facile and efficient strategy to prepare nitrogen-doped hierarchically porous carbon spheres was developed via co-pyrolyzation of poly(vinylidene chloride) and melamine in alginate gel beads. In this approach, melamine not only serves as the nitrogen precursor, but also acts as a template for the macropores structures. The nitrogen contents in the hierarchically porous carbon spheres reach a high level, ranging from 11.8 wt% to 14.7 wt%, as the melamine amount increases. Owing to the enriched nitrogen functionalities and the special hierarchical porous structure, the carbon spheres exhibit an outstanding CO_2 capture performance, with the dynamic capacity of as much as about 7 wt% and a separation factor about 49 at 25 °C in a gas mixture of CO_2/N_2(0.5:99.5, v/v).展开更多
The electrochemical hydrogenation of HMF to BHMF is an elegant alternative to the conventio nal thermocatalytic route for the production of high-value-added chemicals from biomass resources.In virtue of the wide poten...The electrochemical hydrogenation of HMF to BHMF is an elegant alternative to the conventio nal thermocatalytic route for the production of high-value-added chemicals from biomass resources.In virtue of the wide potential window with promising Faradic efficiency(FE) towards BHMF,Cu-based electrode has been in the center of investigation.However,its structure-activity relationship remains ambiguous and its intrinsic catalytic activity is still unsatisfactory.In this work,we develop a two-step oxidation-reduction strategy to reconstruct the surface atom arrangement of the Cu foam(CF).By combination of multiple quasi-situ/in-situ techniques and density functional theory(DFT) calculation,the critical factor that governs the reaction is demonstrated to be facet effect of the metallic Cu crystal:Cu(110) facet accounts for the most favorable surface with enhanced chemisorption with reactants and selective production of BHMF,while Cu(100) facet might trigger the accumulation of the by-product 5,5'-bis(hydroxy methy)hydrofurion(BHH).With the optimized composition of the facets on the reconstructed Cu(OH)_(2)-ER/CF,the performance could be noticeably enhanced with a BHMF FE of 92.3% and HMF conversion of 98.5% at a potential of -0.15 V versus reversible hydrogen electrode(vs.RHE) in 0.1 M KOH solution.This work sheds light on the incomplete mechanistic puzzle for Cu-catalyzed electrochemical hydrogenation of HMF to BHMF,and provides a theoretical foundation for further precise design of highly efficient catalytic electrodes.展开更多
A binder-free Ir-dispersed ordered mesoporous carbon（Ir-OMC） catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with ir...A binder-free Ir-dispersed ordered mesoporous carbon（Ir-OMC） catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with iridium precursors onto the three-dimensional nickel foam framework, followed by insitu calcination in Natmosphere at 800 ℃ for 3 h. This electrode shows a large surface area, ordered mesoporous structure and homogeneous distribution of metal nanoparticles. It presents good activity and stability towards hydrogen evolution reaction, which is attributed to the efficient mass and electron transport from the intimate contact among Ir nanoparticles, ordered mesoporous carbon matrix and 3 D conductive substrate. We hope that this in-situ carbonization synthetic route can also be applied to design more high-performance catalysts for water splitting, fuel cells and other clean energy devices.展开更多
The hydrogen evolution reaction(HER) – as an essential half reaction in water electrolysis and chlor-alkali process has been well studied in acidic electrolyte, but much less has been known in basic medium. In this s...The hydrogen evolution reaction(HER) – as an essential half reaction in water electrolysis and chlor-alkali process has been well studied in acidic electrolyte, but much less has been known in basic medium. In this study, by combining kinetic modeling and electrochemical measurements, we show that hydrated alkali cation clusters can adsorb on the surface of HER catalyst in basic electrolyte. The bound H2 O molecules in the "clusters" can thus be in-situ activated through the hydration effect, which dissociate on the catalyst surface as the reactant of HER. The effective concentration and hydration energy of alkali cation can influence the H2 O dissociation rate, and hence the kinetics of HER. Our work demonstrates a new understanding of the HER mechanism in basic reaction electrolyte.展开更多
基金supported by the National Key R&D Program of China(2022YFB4300700)National Natural Science Foundation of China(22008230,22208021,21925803)+6 种基金China Postdoctoral Science Foundation funded project(2020M670807)the Doctoral Scientific Research Foundation of Liaoning Province(2022-BS-014)the Innovation Research Fund Project of Dalian Institute of Chemical Physics(DICP I202224)CAS Specific Research Assistant Funding Programthe fund of the State Key Laboratory of Catalysis in Dalian Institute of Chemical Physics(N-22-08)the Youth Innovation Promotion Association CAS(Y2022061)the Young Topnotch Talents of Liaoning Province(XLYC2203108)。
文摘The catalytic performance of supported metal catalysts is highly dependent on the interfacial contact between the metal centers and support materials,which could dynamically adapt to the chemical environment in the reactions.Herein,the well-known Ru/TiO_(x)interface of the Ru/TiO_(2)catalyst is shown to be transformed into Ru/TiO_(x)N_(y)during the NH_(3)decomposition,which is derived from the nitridation of the support by N^(*)species.Through a series of characterizations and density functional theory(DFT)calculations,it is found that such a nitrogenous interface primarily blocks the cleavage of N-H bonds with a higher energy barrier,leading to the deactivation of Ru/TiO_(2)in NH_(3)decomposition.Nevertheless,the Ru/TiO_(x)interface can be easily restored by oxidation and a subsequent H2 reduction,contributing to the recovery of the catalytic activity toward NH_(3)decomposition.Our study provides a new insight into the deactivation mechanism of Ru/TiO_(2)in NH_(3)decomposition and highlights the significance of the dynamic evolution of the metal-support interfaces in the reactions.
基金supported by the National Key R&D Program of China (2016YFB0600902)the Dalian National Laboratory for Clean Energy (DNL180401)the National Natural Science Foundation of China (21925803)。
文摘Synthesis of spherical carbon beads with effective CO_2 capture capability is highly desirable for large scale application of CO2 sorption, but remains challenging. Herein, a facile and efficient strategy to prepare nitrogen-doped hierarchically porous carbon spheres was developed via co-pyrolyzation of poly(vinylidene chloride) and melamine in alginate gel beads. In this approach, melamine not only serves as the nitrogen precursor, but also acts as a template for the macropores structures. The nitrogen contents in the hierarchically porous carbon spheres reach a high level, ranging from 11.8 wt% to 14.7 wt%, as the melamine amount increases. Owing to the enriched nitrogen functionalities and the special hierarchical porous structure, the carbon spheres exhibit an outstanding CO_2 capture performance, with the dynamic capacity of as much as about 7 wt% and a separation factor about 49 at 25 °C in a gas mixture of CO_2/N_2(0.5:99.5, v/v).
基金supported by the National Natural Science Foundation of China (21808035, 21901040)the Natural Science Foundation of Fujian Province (2019J05058, 2021J05216, 2022J01922)+3 种基金the Fujian Provincial Department of Finance (GY-Z220231)the fund of the State Key Laboratory of Catalysis in DICP (N-22-08)the Fujian Fishery Disaster Reduction Center (GY-H-22146)College Student Innovation and Entrepreneurship Training Program (x202110388068)。
文摘The electrochemical hydrogenation of HMF to BHMF is an elegant alternative to the conventio nal thermocatalytic route for the production of high-value-added chemicals from biomass resources.In virtue of the wide potential window with promising Faradic efficiency(FE) towards BHMF,Cu-based electrode has been in the center of investigation.However,its structure-activity relationship remains ambiguous and its intrinsic catalytic activity is still unsatisfactory.In this work,we develop a two-step oxidation-reduction strategy to reconstruct the surface atom arrangement of the Cu foam(CF).By combination of multiple quasi-situ/in-situ techniques and density functional theory(DFT) calculation,the critical factor that governs the reaction is demonstrated to be facet effect of the metallic Cu crystal:Cu(110) facet accounts for the most favorable surface with enhanced chemisorption with reactants and selective production of BHMF,while Cu(100) facet might trigger the accumulation of the by-product 5,5'-bis(hydroxy methy)hydrofurion(BHH).With the optimized composition of the facets on the reconstructed Cu(OH)_(2)-ER/CF,the performance could be noticeably enhanced with a BHMF FE of 92.3% and HMF conversion of 98.5% at a potential of -0.15 V versus reversible hydrogen electrode(vs.RHE) in 0.1 M KOH solution.This work sheds light on the incomplete mechanistic puzzle for Cu-catalyzed electrochemical hydrogenation of HMF to BHMF,and provides a theoretical foundation for further precise design of highly efficient catalytic electrodes.
基金support of the National Natural Science Foundation of China (21403218, 21476226, 21403029)Ministry of Science and Technology of the People’s Republic of China under contact of 2016YFA0202800+2 种基金the Youth Innovation Promotion Association of the CASthe Scientific Research Project of the Education Department of Liaoning Province (L2014022)the Fundamental Research Funds for the Central Universities (DUT15ZD225)
文摘A binder-free Ir-dispersed ordered mesoporous carbon（Ir-OMC） catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with iridium precursors onto the three-dimensional nickel foam framework, followed by insitu calcination in Natmosphere at 800 ℃ for 3 h. This electrode shows a large surface area, ordered mesoporous structure and homogeneous distribution of metal nanoparticles. It presents good activity and stability towards hydrogen evolution reaction, which is attributed to the efficient mass and electron transport from the intimate contact among Ir nanoparticles, ordered mesoporous carbon matrix and 3 D conductive substrate. We hope that this in-situ carbonization synthetic route can also be applied to design more high-performance catalysts for water splitting, fuel cells and other clean energy devices.
基金support from the National Natural Science Foundation of China (21808035)the Scientific Research Project of the Education Department of Fujian Province (JT180343, JT180089)+5 种基金the Fundamental Research Funds of FJUT (GY-Z18041, GY-Z160120)the Youth Innovation Project in the Natural Science Foundation of Fujian Province (2019J05058)the University Program for Outstanding Youth Scientific Research Talent Training in Fujian Province (GY-Z18162)the Quangang Petrochemical Research Institute of Fujian Normal University (2017YJY10)the Scientific Research Project of the Education Department of Liaoning Province (L2014022)the Fundamental Research Funds for the Central Universities (DUT15ZD225)。
文摘The hydrogen evolution reaction(HER) – as an essential half reaction in water electrolysis and chlor-alkali process has been well studied in acidic electrolyte, but much less has been known in basic medium. In this study, by combining kinetic modeling and electrochemical measurements, we show that hydrated alkali cation clusters can adsorb on the surface of HER catalyst in basic electrolyte. The bound H2 O molecules in the "clusters" can thus be in-situ activated through the hydration effect, which dissociate on the catalyst surface as the reactant of HER. The effective concentration and hydration energy of alkali cation can influence the H2 O dissociation rate, and hence the kinetics of HER. Our work demonstrates a new understanding of the HER mechanism in basic reaction electrolyte.
