Boosting Activity and Selectivity of UiO‐66 through Acidity/Alkalinity Functionalization in Dimethyl Carbonate Catalysis

Abstract

The acid–base properties of supports have an enormous impact on catalytic reactions to regulate the selectivity and activity of supported catalysts. Herein, a train of Pd‐X‐UiO‐66 (X = NO2, NH2, and CH3) catalysts with different acidity/alkalinity functional groups and encapsulated Pd(II) species is first developed, whose activities in dimethyl carbonate (DMC) catalysis are then investigated in details. Thereinto, the Pd‐NO2‐UiO‐66 catalyst with acidity functionalization exhibits the best catalytic behavior: the DMC selectivity stemmed from methyl nitrite (MN) is up to 68%, the conversion of CO is 73.4%. The obtained experimental results demonstrate that the NO2 group not only affected the interaction between X‐UiO‐66 and Pd(II) active sites but also play an indispensable role in the adsorption and activation of MN and CO, which remarkably promote the formation of the COOCH3* intermediate and DMC product.

GSH-depleting metal–polyphenol-network nanoparticles with dual enzyme activities induce enhanced ferroptosis

“…The surface area of Ce-aMOFs was derived to be ca. 6.69 m 2 g −1 , which was significantly smaller than that reported in the references for normal MOFs 40,41 (Fig. 1C), due to the non-porous feature of aMOFs.…”

Evaluating the Role of Functional Groups in the Selective Capture of Ag(I) onto UiO-66-Type Metal–Organic Frameworks

“…were synthesized following our previous reports with slight adjustments. 19,20 More details were provided in Text S1 of the Supporting Information.…”

“…UiO-66-X (X = −(OH) 2 , −(COOH) 2 , −NO 2 , −NH 2 , −SO 3 H, −(SH) 2 ) were synthesized following our previous reports with slight adjustments. , More details were provided in Text S1 of the Supporting Information.…”

A Review of Catalysts for Synthesis of Dimethyl Carbonate

“…Metal-organic framework materials (MOFs), which are crystalline porous materials composed of metal ions or metal clusters and organic ligands, have attracted extensive attention in recent years. In particular, as a catalyst carrier, it is expected to obtain a stable catalyst for the preparation of DMC with high selectivity by stabilizing the Pd active site through MOFs [66][67][68][69][70][71].…”

“…However, Pd/UiO-66, which had fewer interfaces and fewer Lewis acid sites, was around the Pd NPs and followed a different reaction pathway to provide DMO products, as shown in Figure 2. Tuning the microenvironment of metal nanoparticles provides important insights into their optimized electronic states and activity; moreover, it opens up a new avenue for selective modulation by controlling the position of the active metal site relative to the porous support in heterogeneous catalysis [66,67,71].…”