SiCl4-Modified layered double hydroxides for boosting CO selectivity in CO2 hydrogenation: increasing selectivity from 20% to nearly 100%

Abstract

Silicon tetrachloride (SiCl₄), the major byproduct of the Siemens process for polysilicon production, is essential for the modern electronics and semiconductor industries but has limited value and poses significant environmental challenges if not upcycled properly. Beyond converting it into common silicon products, recent research has shown its promise in advanced energy and catalysis fields. Herein, we report that the modification of a leading catalyst material—layered double hydroxides (LDHs)—with SiCl₄ can significantly alter the product selectivity of heterogeneous CO₂ hydrogenation. Specifically, SiCl₄ exfoliates and covers CoZnAl–LDH, disrupting the layered structure, altering the electronic structure, and shifting the pathway from deep hydrogenation towards CH₄ to directly produce CO. This work provides new insights into the potential of SiCl₄ as a reagent for the synthesis of efficient catalysts for advanced energy catalysis.