SiCl4-Modified Layered Double Hydroxides for Boosting CO Selectivity in CO2 Hydrogenation: Achieving Nearly 100% from Baseline 20%

Abstract

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