The effect of Pd(II) chloride complexes anchoring on the formation and properties of Pd/MgAlOx catalysts.

• Purposeful change of palladium species localization in LDH structure. • Effect of precursor localization on sizes and morphology of supported Pd. • Effect of Pd precursor fixing on palladium activity in aqueous-phase FAL hydrogenation. • Predominant route of FAL conversion through furan ring hydrogenation on Pd/MgAl-LDH. Pd(II) chloride complexes were anchored using magnesium-aluminum layered double hydroxides (LDHs) with interlayer anions (CO 3 2– and OH–), which possess different exchange properties, and MgAl mixed oxide during its rehydration. It was shown that the catalysts of the same chemical composition with different size, morphology and electronic state of supported palladium particles can be synthesized by varying the localization of Pd precursor. The properties of Pd/MgAlOx catalysts were studied in aqueous-phase hydrogenation of furfural. Anchoring of the Pd precursor in the interlayer space of LDHs is accompanied by the formation of non-isometric agglomerated palladium particles which contain less oxidized metal and show a higher activity toward hydrogenation of furfural. Magnesium-aluminum oxides in Pd/MgAlO x catalysts are rehydrated in the aqueous-phase reaction to yield the activated MgAl-LDH species as a support, which promotes the furfural conversion via hydrogenation of the furan cycle. [ABSTRACT FROM AUTHOR]