Zhendong Liu 교수

Encapsulating metal nanoclusters into zeolites combines the superior catalytic activity of the nanoclusters with high stability and unique shape selectivity of the crystalline microporous materials. The preparation of such bifunctional catalysts, however, is often restricted by the mismatching in time scale between the fast formation of nanoclusters and the slow crystallization of zeolites. We herein demonstrate a novel strategy to overcome the mismatching issue, in which the crystallization of

The hydrothermal synthesis of zeolites carried out in batch reactors takes a time so long (typically, on the order of days) that the crystallization of zeolites has long been believed to be very slow in nature. We herein present a synthetic process for ZSM-5, an industrially important zeolite, on the order of seconds in a continuous flow reactor using pressurized hot water as a heating medium. Direct mixing of a well-tuned precursor (90 °C) with the pressurized water preheated to extremely high

Herein, we report a rapid route for the synthesis of AlPO4-5. By combining fast heating in a tubular reactor with a seed-assisted method, both of which were found to be crucial, the preparation of AlPO4-5 was completed in one minute, making this route the fastest known for the preparation of the crystalline microporous materials.

Herein we review the concepts, challenges and recent developments on the continuous flow synthesis of ordered porous materials.

We herein present a top-down methodology to prepare nanosized zeolites with tunable size by combining post-synthesis milling and fast recrystallization of several minutes (10 min for SSZ-13 and 5 min for AlPO4-5). A continuous-flow recrystallization process is demonstrated to further enhance the overall product efficiency.

Crystalline microporous materials have been typically synthesized by long-time hydrothermal treatment in a batch reactor, which suffers from drawbacks like frequent start-up and shut-down operations and low energy efficiency. The development of a continuous flow process for the synthesis of crystalline microporous materials is extremely challenging due to the slow crystallization of the microporous materials. In this work, we demonstrate the continuous flow synthesis of an important crystalline

We herein report that a copper-ion-exchanged erionite zeolite (Cu-ERI) exhibited a methanol yield as high as 147 μmol/g-zeolite, equaling 0.224 μmol/μmol-Cu, in the direct oxidation of methane to methanol. Moreover, this high methanol yield was achieved using an isothermal chemical looping with both oxygen activation and reaction with methane carried out at 300 °C, in contrast to the conventional stepwise protocol where activation is performed at a high temperature (450 °C and above) and the met

In this work, a new controllable and continuous free radical polymerization process was developed and characterized in a coaxial capillary microreactor. In this process, the monomer solution was first dispersed into monodispersed droplets followed by thermal-initiated polymerization in the following capillary immersed in an oil bath. Poly(butyl acrylate) prepared in this microreactor possessed a much higher average molecular weight (Mn) and far lower polydispersity index (PDI) than that produced

Ion flotation is a separation process involving the adsorption of a surfactant and counterions at an air/aqueous solution interface. It shows great promise for removing toxic heavy metal ions from dilute aqueous solutions. It was found that a chelating surfactant, dodecyldiethylenetriamine (Ddien), could selectively remove one metal ion over others at different pH values. Selectivity was attributed to the formation of surface-active chelated species at specific pH. Surface tension data show that

Silicoaluminophosphates are a class of crystalline microporous materials that have been widely used as catalysts and adsorbents. Two representative silicoaluminophosphates, SAPO-CHA (also called SAPO-34) and SAPO-AFI (also called SAPO-5), were synthesized in a tubular reactor within 10 and 5 min, respectively. The addition of a milled seed with small crystal size, the pretreatment of Al and Si sources by mechanical milling, and the employment of a high temperature condition were found to be the

Abstract Characteristics of zeolite formation, such as being kinetically slow and thermodynamically metastable, are the main bottlenecks that obstruct a fast zeolite synthesis. We present an ultrafast route, the first of its kind, to synthesize high‐silica zeolite SSZ‐13 in 10 min, instead of the several days usually required. Fast heating in a tubular reactor helps avoid thermal lag, and the synergistic effect of addition of a SSZ‐13 seed, choice of the proper aluminum source, and employment of

N₂O is typically present as a trace gas in chemical processes, but its emission causes serious environmental issues. We herein demonstrate that ion-exchanged mordenite zeolites (framework code: MOR) can exhibit high capacities for N₂O adsorption under ambient conditions. In particular, a natural MOR zeolite gives an adsorption capacity as high as 0.34 mmol-N₂O per g-zeolite (1 atm, 25 °C), representing the best performing material among all zeolite-based adsorben

We study the interaction of a three-level atom with cavity fields of arbitrary detunings. We address ourselves in this paper to the question of how the time evolution of a coherent state depends upon the detunings. A number of interesting new phenomena contrary to the existing picture are found and discussed.