High Surface Area Metal Fluorides as Catalysts

Strain-Engineered Multiferroicity inPnmaNaMnF3Fluoroperovskite

“…We also note that several higher frequency A g and B 2u modes also strongly contribute to the B-field induced distortions, which means that the ME response is also related to phonon mode distortions that are different than the one responsible for the spontaneous ferroelectric polarization, this mechanism being dominant for tensile strains [44]. From the industrial point of view, fluorides have proven to be of high interest for numerous long term applications, such as fluorides-based glasses with a large thermal expansion, low refractive and non-linear index [45,46], strong magnets with an optically transparency in the visible light [47,48], electrochemical devices, solid-state batteries, gas sensors, and electrochromic systems [49] or catalyst surfaces in base of metal fluorides such as AlF 3 [50]. Thus, adding multiferroic properties in fluoroperovskites would open an exciting opportunity to their use (∆Pi) versus magnetic field in strained NaMnF3 (P na21 phase).…”

Time-Optimized 15N qNMR Determination of Lewis and Brønsted Site Concentrations and Chemical Bonding of Pyridine at Brønsted Sites in Amorphous Aluminum Hydroxide Fluoride

“…Recent studies have demonstrated that these metal hydroxide(oxide) fluorides are highly active and selective heterogeneous catalysts due to their tunable Lewis to Brønsted functionality in combination with their nanoscopic topology. − The advantage of these new phases is that their Brønsted to Lewis properties do not only depend on the calcination temperature, but can be chemically adjusted via the F to OH(O) ratio. Typically, these fluorides are X-ray amorphous, exhibit high surface areas, and have particle sizes in the lower nanometer scale range.…”

Rational design of MgF2catalysts with long-term stability for the dehydrofluorination of 1,1-difluoroethane (HFC-152a)

“…Therefore, the manipulation of the synthesis method offers an intelligent way to modify the surface property and create a surface disordered MgF 2 material to produce mediumstrength Lewis acid sites on the surface. This can be explained by the Tanabe model where the surface acidity of MgF 2 is generated from the excessive positive charge caused by the coordinated unsaturated Mg 2+ ions on the surface; 14 the generation of high surface area is oen accompanied by the production of large amount of acid sites; 15 therefore, signicant research efforts have been focused on the synthesis of highsurface area MgF 2 (HS-MgF 2 ). [16][17][18][19][20][21][22][23] Kemnitz et al 17 have successfully synthesized amorphous nano-sized MgF 2 with the high surface area of 150-350 m 2 g À1 via a non-aqueous uorolytic sol-gel method.…”