Suchergebnisse

We first report the systematic control of the reactivity of HO vapor in metal-organic frameworks (MOFs) with Pt nanocrystals (NCs) through ligand functionalization. We successfully synthesized Pt NCs covered with a water-stable MOF, UiO-66 (Pt@UiO-66), having different metal ions or functionalized ligands. The ligand functionalization of UiO-66 significantly affected the catalytic performance of the water-gas shift reaction, and the replacement of Zr ions with Hf ions in UiO-66 had no impact on the catalytic activity. The introduction of a -Br group lowered the reactivity of Pt@UiO-66 by nearly half, whereas the substitution of -Br with a -Me group triply enhanced the activity. The origin of the enhanced catalytic activity was found to be the change in HO activity in the UiO-66 pores by the ligand functionalization, which was investigated using HO sorption, solid-state NMR, X-ray photoelectron spectroscopy, and in situ IR measurements. This work opens a new prospect to develop MOFs as a platform to activate HO. ; This work was supported by JSPS Grants-in-Aid for Scientific Research (B) (No. 15H03784), JSPS Grant-in-Aid for Research Activity start-up (No. 19K23648), JSPS Research Fellow (No. 17J10099), JST PRESTO (No. JPMJPR1514), and Spanish Government-MINECO through "Severo Ochoa" Excellence Programme (SEV-2016-0683).