Тип публикации: статья из журнала
Год издания: 2020
Идентификатор DOI: 10.1016/j.cattod.2020.07.009
Ключевые слова: cu(ii)-hydroxides, one-electron oxidant, oxygen evolution reaction, photocatalytic water splitting, zeolites
Аннотация: Water oxidation is the bottleneck of the water splitting process. A novel highly efficient and stable for many cycles heterogeneous Cu-contained catalysts supported on MFI-type zeolite (1% Cu-ZSM-5) for water oxidation were prepared. Oxo/hydroxo complexes of copper (II) were stabilized in the zeolite channels via polycondensation. Показать полностьюThe analysis of the electron states of copper in the Cu-containing zeolite-based catalysts using EPR and UV–vis DR techniques revealed that the catalytic efficiency of Cu(II) state in zeolite grew up in the series: [Cu(NH3)4]2+ < isolated [Cu(H2O)6]2+ << Cu(OH)x-like and CuOx-like nanoclusters in mesopores << CuOx-like and Cu(OH)x-like complexes in channels < [Cu2(OH)2]2+ complexes in channels. The catalyst containing [Cu2(OH)2]2+ complexes in channels provided the yields of oxygen as high as 60 and 64 % of the stoichiometric quantity at pH 9.2–10.0 in the dark reaction with one-electron oxidant Ru(bpy)33+. Nevertheless, Cu(OH)x-like and [Cu2(OH)2]2+ complexes stabilized in the ZSM-5 channels decomposed easily under the conditions of the photocatalytic reaction. At the same time, the oxygen yield reached 92 % in photocatalytic system Ru(bpy)32+/S2O82− in the presence of 1%Cu-ZSM-5 containing CuOx-like complexes stabilized in the channels. The adsorption of Ru(bpy)32+ on the surface of 1%Cu-ZSM-5 containing CuOx-like complexes provided the increase of the reaction rate in 1.6 times and achieved the oxygen yield up to 98 % to stoichiometry. This indicated the strong effect of concurrent processes of Ru(bpy)32+ and Ru(bpy)33+ adsorption/desorption at the catalyst active site on the rate of oxygen evolution. © 2020
Журнал: Catalysis Today
ISSN журнала: 09205861
Издатель: Elsevier B.V.