Vermiculite reshaped nickel-based hydrotalcite derived composites efficiently drive methane dry reforming

Abstract

Dry reforming of methane (DRM) presents a promising approach for the large-scale conversion of CO₂ into syngas, thereby holding significant potential in mitigating climate change. However, the primary challenge lies in developing highly efficient catalysts that exhibit both resistance to sintering and carbon deposition. In this study, we leveraged the two-dimensional characteristics of vermiculite (VMT), a naturally occurring layered silicate material. We innovatively utilized the surface charge matching properties between VMT nanosheets and layered double hydroxides (LDHs) to construct a VMT@Ni₂-Mg₂Al composite catalyst via an electrostatic self-assembly strategy. Performance tests demonstrated that this material exhibited superior catalytic performance in the DRM reaction, achieving highly efficient simultaneous conversion of CH₄ (87.45%) and CO₂ (91.26%). Characterization analysis revealed that the VMT nanosheets, acting as a structural support, stabilized the uniform dispersion and anchoring of Ni nanoparticles through the confinement effect provided by the LDHs. The introduction of the Mg component enhanced the metal–support interaction and significantly improved the electron-rich state on the surface of the Ni active centers, thereby enhancing the C–H bond dissociation ability; additionally, it provided abundant CO₂ adsorption/activation sites. In situ DRIFTS highlights the importance of electron-rich metal Ni sites and surface alkaline sites in promoting CH₄ dissociation and CO₂ activation. This contributes to the enhanced resistance to sintering and coking of VMT@Ni₂-Mg₂Al, providing an innovative design concept for the development of clay mineral-based high-efficiency DRM catalysts.