Four natural clays were modified with mixed polyoxocations of Al/Fe for evaluating the effect of the physicochemical properties of the starting materials (chemical composition, abundance of expandable clay phases, cationic exchange capacity and textural properties) on final physicochemical and catalytic properties of Al/Fe-PILCs. The aluminosilicate denoted C2 exhibited the highest potential as starting material in the preparation of Al/Fe-PILC catalysts, mainly due to its starting cationic exchange capacity (192 meq/100 g) and the dioctahedral nature of the smectite phase. These characteristics favored the intercalation of the mixed (Al13−x/Fex)7+ Keggin-type polyoxocations, stabilizing a basal spacing of 17.4 Å and high increase of the BET surface (194 m2/g), mainly represented in microporous content. According to H2-TPR analyses, catalytic performance of the incorporated Fe in the Catalytic Wet Peroxide Oxidation (CWPO) reaction strongly depends on the level of location in mixed Al/Fe pillars. Altogether, such physicochemical characteristics promoted high performance in CWPO catalytic degradation of methyl orange in aqueous medium at very mild reaction temperatures (25.0 ± 1.0 °C) and pressure (76 kPa), achieving TOC removal of 52% and 70% of azo-dye decolourization in only 75 min of reaction under very low concentration of clay catalyst (0.05 g/L).
The synthesis of new enantiopure wide‐bite‐angle diphosphanes is described as well as their use in the palladium‐catalyzed asymmetric fluorination of α‐cyanoacetates. Enantiomeric excesses up to 93 % were obtained when Pd(OAc)2‐SPANphos was used as catalyst for the fluorination of ethyl 2‐cyano‐2‐phenylacetate with N‐fluorobenzenesulfonimide (NFSI).
10 kg scale, significantly intensified preparation of Al/Fe-PILCs from intercalating solution ∼100 times more concentrated than usual and powered clay.
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