The Impact of Synthesis Method on the Properties and CO2 Sorption Capacity of UiO-66(Ce)

Abstract

A series of cerium-based UiO-66 was obtained via hydrothermal and sonochemical methods, using the same quantities of reagents (cerium ammonium nitrate (CAN), terephthalic acid (H2BDC)) and solvents) in each synthesis. The impact of synthesis method and metal to linker ratio on the structural and textural properties of obtained UiO-66(Ce), as well as their composition in terms of Ce4+/Ce3+ ratio, structure defects resulting from missing linker, and CO2 adsorption capacity was discussed. By using typical characterization techniques and methods, such as XRD, N2 and CO2 sorption, TGA, XPS, and SEM, it was shown that the agitation of reacting mixture during synthesis (caused by stirring or ultrasounds) allows to obtain structures that have more developed surfaces and fewer linker defects than when MOF was obtained in static conditions. The specific surface area was found to be of minor importance in the context of CO2 adsorption than the contribution of Ce3+ ions that were associated with the concentration of linker defects.

CO2 Hydrogenation to Methanol over Ce and Zr Containing UiO-66 and Cu/UiO-66

“…As was reported in [36,37] the UiO-66(Ce) was stable only up to 220−240 • C. Also our studies revealed that complete exchange of Zr for Ce in the UiO-66 shifted the temperature of BDC decomposition to ca. 260−280 • C (depending on the synthesis method) which was followed with the collapse of MOF structure [38]. Compared to UiO-66(Zr) and UiO-66(Ce/Zr), a significant decrease in thermal stability, by ca.…”

“…Catalysts 2019, 9, x FOR PEER REVIEW 9 of 17 ca. 260−280 °C (depending on the synthesis method) which was followed with the collapse of MOF structure [38]. Compared to UiO-66(Zr) and UiO-66(Ce/Zr), a significant decrease in thermal stability, by ca.…”

“…The Cu-containing catalysts were pre-reduced in H 2 /Ar prior to the tests to provide Cu 0 active sites for H 2 dissociation, but CuO reduction might have not been completed and except for Cu 0 , the cationic copper (e.g. Cu 2 O) could have been also present on the catalyst surface [38]. It is known that the combination of Cu species plays important role in the catalyst performance: the Cu 0 is responsible for H 2 dissociation, whereas Cu + stabilizes the formate intermediates.…”

Application of Various Metal-Organic Frameworks (MOFs) as Catalysts for Air and Water Pollution Environmental Remediation

“…In addition, Salama et al, reported an SO2 gas sensor while using an MOF [12]. Metal-organic frameworks (MOFs) have a wide range of interesting properties such as high specific surface area and facile modification [13][14][15][16][17][18][19][20][21][22][23][24][25][26]. MOFs are microporous materials that form three-dimensional (3D) crystalline networks, which are prepared by combining various metal ions with organic linkers in an appropriate solvent [27][28][29][30][31][32].…”

Electrochemical and photocatalytic applications of Ce-MOF

“…Here we have reported, synthesis, characterization and applications of Ce-MOF. In comparison with the solvothermal and hydrothermal synthesis [6], the stirring route is low cost and environmentally friendly. Hence we successfully synthesized cerium benzene dicarboxylic acid (Ce-bdc) MOF by a simple, cost-effective method with green strategy.…”