Dually Confined Ni-based Catalysts by Ion-Exchange Inverse Loading for Dry Reforming of Methane

摘要

Producing syngas from dry reforming of methane is fascinating but challenging because of coking and sintering. Herein, fine Ni nanoparticles surrounded by Al2O3 are constructed by ion-exchange inverse loading method. The dual confinement composed of physical barrier originated from Al2O3 surroundings and chemical bonding sourced from NiAl2O4 spinel is present on pitaya-like Ni@Al2O3 catalysts. Mixed acid-base property of Ni@Al2O3 mediates the co-conversion of CH4 and CO2. On the one hand, the acidity of Al2O3, accelerates the pyrolysis of CH4. On the other hand, the basicity originated form ample O2- promotes the chemisorption of CO2 and oxidisation of carbon deposition using CO2 as oxidiser. Based on the dual confinement and cooperation of acid-base sites, Ni@Al2O3 survive severe coking with a CO2 conversion above 85% and no sign of deactivation. The metal-oxide interface is investigated focusing on physical-chemical confinement and properties, including electronic interaction, mixed acid-base property, and chemisorption of probe molecule.

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