The efficiency of photo-electrocatalytic(PECa) devices for the production of solar fuels depends on several limiting factors such as light harvesting, charge recombination and mass transport diffusion. We analyse he...The efficiency of photo-electrocatalytic(PECa) devices for the production of solar fuels depends on several limiting factors such as light harvesting, charge recombination and mass transport diffusion. We analyse here how they influence the performances in PECa cells having a photo-anode based on Au-modified TiOnanotube(TNT) arrays, with the aim of developing design criteria to optimize the photo-anode and the PECa cell configuration for water photo-electrolysis(splitting) and ethanol photo-reforming processes.The TNT samples were prepared by controlled anodic oxidation of Ti foils and then decorated with gold nanoparticles using different techniques to enhance the visible light response through heterojunction and plasmonic effects. The activity tests were made in a gas-phase reactor, as well as in a PECa cell without applied bias. Results were analysed in terms of photo-generated current, Hproduction rate and photoconversion efficiency. Particularly, a solar-to-hydrogen efficiency of 0.83% and a Faradaic efficiency of 91%were obtained without adding sacrificial reagents.展开更多
The supported Au/TiO2 and Au/TiO2-SiO2 catalysts were prepared by deposition precipitation method. The TPD study reveals that propylene oxide competes with propylene to be adsorbed on the same adsorptive center-Ti^n+...The supported Au/TiO2 and Au/TiO2-SiO2 catalysts were prepared by deposition precipitation method. The TPD study reveals that propylene oxide competes with propylene to be adsorbed on the same adsorptive center-Ti^n+ site on the surface of the catalyst and that the adisorbing capacity of the catalyst for propylene oxide is larger than that for propylene. Catalytic behavior for propylene epoxidation with H2 and O2 was tested in a micro-reactor. Under typical conditions, the selectivity for propylene oxide is over 87%. The TG curves show that PO successive oxidation cause carbon deposition on the active center and deactivation of the Au catalysts. Because the amounts of Tin+ site decrease significantly, and consequently the separation between Ti^n+ sites increases, the Au/TiO2-SiO2 catalyst is more stable than Au/TiO2.展开更多
Cold plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure was adopted for preparation of commercial TiO2 Degussa P25 supported Au catalysts (Au/P25- P) with the assistance of the depositi...Cold plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure was adopted for preparation of commercial TiO2 Degussa P25 supported Au catalysts (Au/P25- P) with the assistance of the deposition-precipitation procedure. The influences of the plasma reduction time and calcination on the performance of the Au/P25-P catalysts were investigated. CO oxidation was performed to investigate the catalytic activity of the Au/P25 catalysts. The results show that DBD cold plasma for the fabrication of Au/P25-P catalysts is a fast process, and Au/P25-P (4 min) exhibited the highest CO oxidation activity due to the complete reduction of Au compounds and less consumption of oxygen vacancies. In order to form more oxygen vacancies active species, Au/P25-P was calcined to obtain Au/P25-PC catalysts. Interestingly, Au/P25- PC exhibited the highest activity for CO oxidation among the Au/P25 samples. The results of transmission electron microscopy (TEM) indicated that the smaller size and high distribution of Au nanoparticles are the mean reasons for a high performance of Au/P25-PC. Atmospheric- pressure DBD cold plasma was proved to be of great efficiency in preparing high performance supported Au catalysts.展开更多
基金Projects(52274255,51674067)supported by the National Natural Science Foundation of ChinaProject(2020YFB2008702)supported by the National Key R&D Program of China+4 种基金Projects(N2201008,N2201004)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(XLYC1807160)supported by the Liaoning Revitalization Talents Program,ChinaProject(2022M720025)supported by the China Postdoctoral Science FoundationProject supported by Postdoctoral Foundation of Northeastern University,ChinaProject(2022QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,China。
基金The TERRA(Tandem Electrocatalytic Reactor for energy/Resource efficiency and process intensification,H2020 project 677471)Eco~2CO_2(Eco-friendly biorefinery fine chemicals from CO_2 photo-catalytic reduction,FP7 project 309701)
摘要The efficiency of photo-electrocatalytic(PECa) devices for the production of solar fuels depends on several limiting factors such as light harvesting, charge recombination and mass transport diffusion. We analyse here how they influence the performances in PECa cells having a photo-anode based on Au-modified TiOnanotube(TNT) arrays, with the aim of developing design criteria to optimize the photo-anode and the PECa cell configuration for water photo-electrolysis(splitting) and ethanol photo-reforming processes.The TNT samples were prepared by controlled anodic oxidation of Ti foils and then decorated with gold nanoparticles using different techniques to enhance the visible light response through heterojunction and plasmonic effects. The activity tests were made in a gas-phase reactor, as well as in a PECa cell without applied bias. Results were analysed in terms of photo-generated current, Hproduction rate and photoconversion efficiency. Particularly, a solar-to-hydrogen efficiency of 0.83% and a Faradaic efficiency of 91%were obtained without adding sacrificial reagents.
基金Supported by the National Natural Science Foundation of China (29773031).
摘要The supported Au/TiO2 and Au/TiO2-SiO2 catalysts were prepared by deposition precipitation method. The TPD study reveals that propylene oxide competes with propylene to be adsorbed on the same adsorptive center-Ti^n+ site on the surface of the catalyst and that the adisorbing capacity of the catalyst for propylene oxide is larger than that for propylene. Catalytic behavior for propylene epoxidation with H2 and O2 was tested in a micro-reactor. Under typical conditions, the selectivity for propylene oxide is over 87%. The TG curves show that PO successive oxidation cause carbon deposition on the active center and deactivation of the Au catalysts. Because the amounts of Tin+ site decrease significantly, and consequently the separation between Ti^n+ sites increases, the Au/TiO2-SiO2 catalyst is more stable than Au/TiO2.
基金supported by National Natural Science Foundation of China(Nos.11505019,21173028)the Science and Technology Research Project of Liaoning Provincial Education Department(No.L2013464)+1 种基金the Scientific Research Foundation for the Doctor of Liaoning Province(No.20131004)the Dalian Jinzhou New District Science and Technology Plan Project(No.KJCX-ZTPY-2014-0001)
摘要Cold plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure was adopted for preparation of commercial TiO2 Degussa P25 supported Au catalysts (Au/P25- P) with the assistance of the deposition-precipitation procedure. The influences of the plasma reduction time and calcination on the performance of the Au/P25-P catalysts were investigated. CO oxidation was performed to investigate the catalytic activity of the Au/P25 catalysts. The results show that DBD cold plasma for the fabrication of Au/P25-P catalysts is a fast process, and Au/P25-P (4 min) exhibited the highest CO oxidation activity due to the complete reduction of Au compounds and less consumption of oxygen vacancies. In order to form more oxygen vacancies active species, Au/P25-P was calcined to obtain Au/P25-PC catalysts. Interestingly, Au/P25- PC exhibited the highest activity for CO oxidation among the Au/P25 samples. The results of transmission electron microscopy (TEM) indicated that the smaller size and high distribution of Au nanoparticles are the mean reasons for a high performance of Au/P25-PC. Atmospheric- pressure DBD cold plasma was proved to be of great efficiency in preparing high performance supported Au catalysts.