Mass Transfer Modulation by Hollow Multi‐Shelled Structures for High Space‐Time Yield Synthesis of Light Olefins from Syngas

Abstract

The separation of CO activation and C─C coupling enables oxide–zeolite catalyzed tandem reaction toward direct conversion of syngas into light olefins to be a promising alternative for the traditional Fischer–Tropsch process with elevated selectivity. Utilizing controlled mass transfer to match the activation of reactants and the coupling of intermediates presents an appealing strategy to break the limitation on space‐time yield in this tandem process. In this work, ZnCrOx hollow multi‐shelled structures (HoMS) are fabricated to enhance the adsorption and enrichment ability of syngas, thereby strengthening the rate‐determining activation step of reactants and resulting in an accelerated generation of intermediates. When coupled with SAPO zeolite, quintuple‐shelled ZnCrOx HoMS‐based catalysts exhibit a record high C2 = ‐C4 = space‐time yield of 559 mg·gcat−1·h−1 with a selectivity of 90%. This work demonstrates the advantages of precise nanostructure sculpturing on the mass transfer behavior in the microenvironment and provides a new strategy for highly selective direct conversion of syngas to light olefins, based on efficient activation of reactants and sufficient feeding of intermediates through enrichment effects within HoMS.

Advancing the Development of Hollow Micro/nanostructured Materials for Electrocatalytic Water Splitting: Current State, Challenges, and Perspectives

“…In hollow structures, regulating the shell part could tune the mass transport during catalytic reactions. − The chemical compositions of catalysts can be modified by analyzing the binding energy of adsorbents and desorption of intermediates on the catalyst surface. − Furthermore, the micro/nanostructures can significantly enhance the utilization and decrease the consumption of costly precious metals, which can function as direct electrocatalysts or hosts for loading active materials toward water splitting. , Hollow materials offer multiple surface active sites for catalyzing water splitting, in which the active components can be placed into the channel or pore walls, inner cavities, or inner or outer surfaces and also can be enclosed within the framework to create heterostructures. Additionally, hollow micro/nanostructures are used to improve the efficacy of active species by increasing the electrolyte retention time within the pores of hollow catalytic materials.…”