Congratulations to Miao Guo whose paper on Improving the catalytic performance of Pd nanoparticles by electronic modulation using phosphine ligands for hydrogenation reactions has been published in ACS Catalysis (DOI: 10.1021/acscatal.8b00872).
Tuning the activity and selectivity of metal nanoparticles (NPs) is a long term pursuit in the field of catalysis. Herein, we report successfully adjusting both activity and chemoselectivity of Pd NPs (1.1 nm) with triphenylphosphine (PPh3) cross-linked in the nanopore of FDU-12. The electron donating effect of PPh3 increases surface electronic density of Pd NPs and weakens Pd-H bond as evidenced by results of XPS, in situ FT-IR adsorption of CO and H2-D2 exchange reaction. Consequently, Pd NPs modified with PPh3 obtain > 99 % selectivity to 1-phenylethanol in acetophenone hydrogenation and 94 % selectivity to styrene in phenylacetylene hydrogenation. Furthermore, the activity of Pd NPs is enhanced and suppressed by PPh3 respectively in the hydrogenation of electrophilic and nucleophilic substrates. Our primary results shed some light on judiciously choosing organic ligands for modifying the catalytic performance of metal NPs towards specific chemical transformations.