Elucidating the Role of –NH ₂ in a NH ₂ -MIL-53-Derived Ni/Al ₂ O ₃ Catalyst for Long-Term Dry Reforming of Methane

Dry reforming of methane (DRM) is a promising route for the simultaneous conversion of CO2 and CH4; despite the effectiveness of C–H bond activation ability of Ni-based catalysts, they face serious challenges due to coking. Herein, two metal–organic frameworks (MOFs), NH2-MIL-53 and MIL-53 were loaded with Ni via impregnation and calcined at different temperatures to prepare Ni/Al2O3 catalysts. The results reveal that the Ni-based catalyst derived from NH2-MIL-53 possesses a higher specific surface area (SSA) due to the presence of –NH2 groups, which remarkably improved the dispersion of Ni. Additionally, the calcination temperatures are found to play an important role. Low-temperature calcination leads to weaker metal–support interaction (MSI) while high-temperature calcination results in lower specific surface area (SSA) and agglomeration of the active component Ni. The Ni/Al2O3 catalyst calcined at 850 °C exhibits moderate MSI and high SSA, leading to excellent catalytic activity (CH4 conversion ∼68%, CO2 conversion ∼80%) and stability (>50 h with coking ≈0.022 mmol C·gcat–1·h–1) at 750 °C with a GHSV of 96,000 mL/(gcat·h). The derived porous alumina restricts Ni sintering. In situ DRIFT results show that such a catalyst benefits the formation of key intermediate b-HCOO* due to high Ni dispersion. This work provides new insights and directions for optimizing the performance of MOF-derived catalysts.