Synthesis of atomically dispersed cationic nickel-confined mesoporous ZSM-48 (ANMZ-48) directed by metal complexes in amphiphilic molecules

Abstract

The synthesis of mesoporous zeolite-anchored atomically dispersed metal catalysts (ADCs) is a considerable challenge in chemistry and materials science. Here we report the synthesis of atomically dispersed cationic nickel-confined mesoporous ZSM-48 (ANMZ-48) by in situ hydrothermal reaction employing a designed tri-functional metal complex template, by which the triquaternary ammonium groups in the hydrophilic region direct the formation of ZSM-48 zeolite; the aromatic groups in the hydrophobic tail generate the mesopores through π-π stacking; and the complexes formed by nickel ions coordinated with terpyridyl groups generate atomically dispersed Ni²⁺ confined in zeolite frameworks due to the strong sintering resistance generated by the strong coordination interaction. The ANMZ-48 is consisting of stacking of sheet-like ZSM-48 domains connected by multiply crystal twinning sharing the common (011) plane, generating abundant of imbedded mesopores with the uniform thickness of ∼2.4 nm and with the width of 10–50 nm. The excellent catalytic activity and stability of ANMZ-48 were also reflected in the dry reforming of methane (DRM) reaction.