Design dual confinement Ni@S-1@SiO2 catalyst with enhanced carbon resistance for methane dry reforming

Abstract

Methane dry reforming is a key method for converting greenhouse gases into valuable syngas, providing a pathway for the sustainable production of valuable compounds. Yet the challenges like particle sintering and carbon deposition have hindered the widespread application of nickel-based catalysts. This study explores innovative strategies to overcome these challenges by using zeolite supports to enhance nickel dispersity and prevent carbon deposition, as well as adopting core-shell structures to prevent metal sintering and carbon deposition. In pursuit of enhancing methane dry reforming efficacy, a Ni@S-1@SiO2 dual-shell nickel-based catalyst is designed in this study to confine exposed nickel particles on the S-1 surface within a robust mesoporous silica shell, reducing nickel particle mobility and preventing active site oxidation, thereby increasing resistance to sintering and carbon deposition. Compared to conventional single-core-shell catalysts, this design significantly reduces nickel particle mobility and active site oxidation, enhancing resistance to sintering and coking. It showed virtually no carbon deposition even after a rigorous 25-h reaction at 650 °C. In-situ DRIFTS analyses provided further insights into the underlying mechanism, confirming a Langmuir-Hinshelwood mechanism and highlighting the beneficial role of formates in preventing coke deposition. This study not only advances the understanding of core-shell catalyst structures but also paves the way for optimized nickel-based catalysts in methane dry reforming, promoting a sustainable future for syngas production.