Li Chengyang

Bio: Li Chengyang is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Amine gas treating & Catalysis. The author has co-authored 2 publications.

Hierarchical Zeolites-confined Metal Catalysts and Their Enhanced Catalytic Performances.

Abstract: The confinement of metal species within hierarchical zeolites combines the acidic/basic sites of zeolites, the enhanced mass transfer of mesoporous system, and the inside active metal sites, leading to high activity, unique selectivity, and superior stability in chemicals synthesis, energy and environment catalysis. To date, review on this emerging topic is rarely reported. Herein, we classify five metals-hierarchical zeolites composite (metal@hierarchical zeolites) according to the location of metals on hierarchical structure, including metals located on micropores, intercrystalline mesopores, intracrystalline mesopores, hollow nanobox and mesoporous shells. The synthesis and catalysis applications of metal@hierarchical zeolites composite are provided, highlighting the rational design of catalyst preparation, the improved catalytic efficiency and stability of metal species. Finally, we discuss the current limitations and future opportunities for this emerging field. This Review is expected to inspire more developments and applications of metal@hierarchical zeolites.

Method for preparing five-membered-ring-fused seven-membered homopiperazinone derivative through catalyzed oxidative carbonylation of amino olefin amine

Abstract: The invention discloses a method for preparing a five-membered-ring-fused seven-membered homopiperazinone derivative through catalyzed oxidative carbonylation of an amino olefin amine, which comprisesthe following steps: stirring an amino alkene amide compound serving as a raw material in a solvent at the temperature of 50-150 DEG C for 10-30 hours in the presence of an oxidant and a palladium catalyst under the atmosphere of carbon monoxide; and after the reaction is finished, conducting cooling to room temperature, removing the reaction solvent under reduced pressure, and carrying out silica column chromatography purification on the obtained crude product to obtain the five-membered-ring-fused seven-membered homopiperazinone derivative. In the method, the carbonylation reaction has theadvantages of high activity, high selectivity, few byproducts, mild reaction conditions and simple operation process; and gas participates in the reaction, and the product is low in purification and separation cost and suitable for mass production.

Dynamics-driven Tailoring of Sub-nanometric Pt-Ni Bimetals Confined in Hierarchical Zeolite for Catalytic Hydrodeoxygenation

Abstract: Metal-zeolite catalysts are promising for hydrodeoxygenation of bio-oils, but they always encounter sluggish diffusion kinetics due to sole micropores and inferior metal stability. Here, highly stable sub-nanoscale Pt-Ni bimetals confined in a hierarchical ZSM-5 zeolite ([email protected]) are constructed. The formed [email protected] species create framework-bonding metal sites with zeolite in a confined microenvironment, thereby establishing strong interactions and generating uniform distribution of Pt-Ni bimetals. In the [email protected] hydrodeoxygenation of phenolics, sub-nanometric Pt-Ni facilitates the adsorption and transfer of hydrogen, and hierarchical pores promote the diffusion kinetics of reactants. The designed [email protected] with small metal particles and high coordination numbers of Pt-Ni bonds, favors the complete deoxygenation of phenolics, with a higher yield of cyclohexane than conventional catalysts prepared by impregnation. Benefiting from the protection of the zeolite framework, the [email protected] catalyst exhibits high thermal stability and low leaching of metal active sites, with only 4.4% catalyst deactivation after five reaction cycles.

Selective Production of Petrochemicals through Reactions in Confined Space of Zeolites

Abstract: Zeolites based material are very popular in refining and petrochemicals industries due to their unique properties such as uniform shape and size of pores, moderately higher surface area, and tuneable acidic and basic properties for catalysis. The cavity of a zeolite is an important space for shape selective catalysis as it is accessible to reactants molecules for interaction and adsorption of reactant molecules with active sites available in the pores followed by chemical reaction and diffusion of products. In the present review article, fine tuning of acidic properties and porosity of zeolites on the activity of catalyst and selectivity to desired product for alkylation, trans-alkylation, isomerization reactions, and production of olefins from methanol and syngas are discussed in details.