Ag-Mo-O ternary oxide has attracted growing attention because of its potential as a solid lubricant at high temperatures.This work designs and prepares NiCoCrAlYTa/Ag/Mo composite coating,performed using high velocity...Ag-Mo-O ternary oxide has attracted growing attention because of its potential as a solid lubricant at high temperatures.This work designs and prepares NiCoCrAlYTa/Ag/Mo composite coating,performed using high velocity oxy-fuel(HVOF)spraying technology.The environment temperature plays an important role in the microstructure and phases as well as lubricant properties of NiCoCrAlYTa/Ag/Mo coatings.When the environment temperature is above 600℃,the outer diffusion and oxidation of Ag and Mo lead to the formation of Ag2 MoO4 on the coating surface.Layer-like Ag2 MoO4 could form a continuous lubricant film at 800℃and consequently let the composite coating present the best tribological properties.Meanwhile,a small number of hard particles could play a good bearing role during friction and improve the tribological properties of the composite coating.展开更多
The creation of intergrown layer-like zeolite crystals is one route to form hierarchical zeolites.Faujasite-type(FAU-type)zeolites are among the industrially most important zeolites and the implementation of hierarchi...The creation of intergrown layer-like zeolite crystals is one route to form hierarchical zeolites.Faujasite-type(FAU-type)zeolites are among the industrially most important zeolites and the implementation of hierarchical porosity is a promising way to optimise their catalytic and adsorptive performance.After a short general survey into routes for the preparation of hierarchical pore systems in FAU,we will review the currently existing strategies for the synthesis of FAU with layer-like morphology.Those strategies are mainly based on the presence of morphology modifying agents in the synthesis mixture.However,a very recent approach is the synthesis of layer-like FAU-type zeolite crystals assembled in an intergrown manner in the absence of such additives,just by finely adjusting the crystallization temperature.This additive-free preparation route for layer-like FAU,which appears very attractive from an ecological as well as economic point of view,is highlighted in this review.Concluding,a comparison,including powder X-ray diffraction,scanning and transmission electron microscopy,nitrogen physisorption and elemental analysis,between conventional FAU and three layer-like FAU obtained by different synthesis routes was carried out to show the structural,morphological and textural differences and similarities of these materials.展开更多
基金the financial supports of National Natural Science Foundation of China(Nos.51771214 and 51705481)the Youth Innovation Promotion Association(No.2014378)for Chinese Academy of Sciences。
文摘Ag-Mo-O ternary oxide has attracted growing attention because of its potential as a solid lubricant at high temperatures.This work designs and prepares NiCoCrAlYTa/Ag/Mo composite coating,performed using high velocity oxy-fuel(HVOF)spraying technology.The environment temperature plays an important role in the microstructure and phases as well as lubricant properties of NiCoCrAlYTa/Ag/Mo coatings.When the environment temperature is above 600℃,the outer diffusion and oxidation of Ag and Mo lead to the formation of Ag2 MoO4 on the coating surface.Layer-like Ag2 MoO4 could form a continuous lubricant film at 800℃and consequently let the composite coating present the best tribological properties.Meanwhile,a small number of hard particles could play a good bearing role during friction and improve the tribological properties of the composite coating.
文摘The creation of intergrown layer-like zeolite crystals is one route to form hierarchical zeolites.Faujasite-type(FAU-type)zeolites are among the industrially most important zeolites and the implementation of hierarchical porosity is a promising way to optimise their catalytic and adsorptive performance.After a short general survey into routes for the preparation of hierarchical pore systems in FAU,we will review the currently existing strategies for the synthesis of FAU with layer-like morphology.Those strategies are mainly based on the presence of morphology modifying agents in the synthesis mixture.However,a very recent approach is the synthesis of layer-like FAU-type zeolite crystals assembled in an intergrown manner in the absence of such additives,just by finely adjusting the crystallization temperature.This additive-free preparation route for layer-like FAU,which appears very attractive from an ecological as well as economic point of view,is highlighted in this review.Concluding,a comparison,including powder X-ray diffraction,scanning and transmission electron microscopy,nitrogen physisorption and elemental analysis,between conventional FAU and three layer-like FAU obtained by different synthesis routes was carried out to show the structural,morphological and textural differences and similarities of these materials.
