Effect of organic moieties (phenyl, naphthalene, and biphenyl) in Zr-MIL-140 on the hydrogenation activity of Pd nanoparticles

MIL-140-type metal organic frameworks (isoreticular zirconium oxide MOFs) with different aromatic moieties (phenyl, naphthalene, and biphenyl) have been synthesized and employed as the supports of palladium nanoparticles (Pd NPs). The catalysts were characterized by XRD, BET, TEM and CO chemisorption. The results reveal that Pd NPs are homogeneously dispersed on all materials whereas different accessibility to CO is observed. The hydrogenation performance in C[dbnd]C saturation with respect to the effect of the aromatic moiety is compared. The Pd/MIL-140A MOF with the highest hydrogenation activity among the three catalysts comprised of different aromatic rings points to a unique Pd–π interaction between Pd and frameworks consisting of mono-phenyl groups (C₆H₄).