Oriented synthesis of target products in liquid-phase tandem reaction over a tripartite zeolite capsule catalyst

摘要

Tandem reaction cannot readily realize the precisely controlled synthesis of target products, although it is a promising strategy to improve the utilization efficiency of energy and resources. Changing the assembly style of tandem reaction catalyst from a general hybrid mixture to a well-organized capsule is shown here to be a reasonable way to overcome this problem. In this study, we initially present a novel tripartite zeolite capsule catalyst that consists of a core (Ru/Al2O3)-microporous shell (Silicalite-1)-dopant (Pd) structure. With the liquid-phase tandem reaction of glycerol conversion as a probe reaction, we demonstrate the previously unreported superiority of this tripartite zeolite capsule catalyst on the oriented synthesis of target products. The Pd doped microporous zeolite shell constructs a confined reaction space and provides molecular screening and refining ability to this tripartite zeolite capsule catalyst, which drives it to effectively realize the controlled synthesis of desired chemicals, simultaneously depressing undesired side-reactions very much better than conventional catalyst assemblies. The concept of a catalyst encapsulated by a Pd-doped microporous zeolite shell and its application suggests new opportunities for studying the function of catalyst assembly style in varied tandem reaction systems, the correlations between catalyst assembly style and its catalytic properties, as well as the nature of catalyst active sites and reaction mechanisms. ? 2013 The Royal Society of Chemistry.