Simultaneous incorporation of palladium and zirconium ions in Mg–Al layered double hydroxides by co-precipitation

Simultaneous incorporation of palladium and zirconium ions in Mg–Al layered double hydroxides (LDHs) was attempted by co-precipitation. Mixed oxides were obtained by calcination at 500 °C. XRD patterns of as-synthesized samples showed the formation of well-crystallized LDHs at lower Zr contents. The CO32− content of the solids has been determined to have information on the possible incorporation of Zr4+ into the brucite layer of the hydrotalcites. The values obtained showed that Zr4+ can incorporate into brucite sheets at Zr content lower than 10 mol%. SEM and TEM images indicated that the resulted LDHs with lower Zr content exhibited plate-like structure. Thermal calcination at 500 °C results in the formation of mixed oxides containing MgO, PdO, ZrO2 crystallites and a solid solution formed by some of the Zr4+ cations dissolving along with Al3+ to MgO lattice.

► Simultaneously incorporation of both Pd2+ and Zr4+ into MgAl-LDH layers.
► The CO32– content of the solids was determined.
► The possible incorporation of Zr4+ into the brucite layer was investigated.
► No more than 10 mol% of Zr4+ can be introduced into the layers.
► A promising mixed oxides catalyst can be obtained by calcination at 500 °C.