Sintering of Porous Materials

Influence of hydrothermal, microwave and mechanochemical treatment of tin phosphate on porous structure and catalytic properties

“…These processes are the cause of the decrease in the specific surface area, pore size, and, as a result, catalytic performances. It is well known that sintering ability of porous solids is determined by the size of the particles constituting the framework of a porous solid, and their packing density in the framework [54]. Ultimately, it depends on the pore size and their distribution.…”

“…The latter is the reason for the higher thermal stability of the porous structure of the modified samples compared to the initial one. This primarily relates to the samples modified under the hydrothermal conditions in the form of wet gel: /i/ they contain mesopores with a size of 1.5-2.0 times larger than in the initial sample; /ii/ they do not contain bottle-shaped pores capable to be easily sintered [47,54]. Indeed, the specific surface area for the initial sample containing such pores is reduced by 62 and 94% after its calcinations at 450 and 550 °C, respectively (Table 2).…”

“…This can be explained by the formation of the defect structure during dry milling. As it is commonly known [54], porous solids containing defects are subjected to sintering more easily. The exception is the sample milled in the form of xerogel in water because it possesses bi-porous, namely meso-macroporous, structure (Fig.…”

Wood-Templated CeO2 as Active Material for Thermochemical CO Production

“…Particularly high surface areas are obtained in nanoporous solids. However, pores tend to collapse at high temperatures as grain growth causes the pore walls to fuse together, reducing the active surface area . A recent study by Rudisill et al showed an enhancement of the kinetics of CO production from the CeO 2 cycle by molding the oxide into a three-dimensionally ordered macroporous (3DOM) structure, thereby increasing the specific surface area available for reaction .…”

“…However, pores tend to collapse at high temperatures as grain growth causes the pore walls to fuse together, reducing the active surface area. 17 A recent study by Rudisill et al showed an enhancement of the kinetics of CO production from the CeO 2 cycle by molding the oxide into a three-dimensionally ordered macroporous (3DOM) structure, thereby increasing the specific surface area available for reaction. 9 Yet an instability of the pore structure was observed when the material was cycled at a reduction temperature of 1200 °C due to sintering.…”