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 CO 2 and CH 4; 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), NH 2 -MIL-53 and MIL-53 were loaded with Ni via impregnation and calcined at different temperatures to prepare Ni/Al 2 O 3 catalysts. The results reveal that the Ni-based catalyst derived from NH 2 -MIL-53 possesses a higher specific surface area (SSA) due to the presence of –NH 2 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/Al 2 O 3 catalyst calcined at 850 °C exhibits moderate MSI and high SSA, leading to excellent catalytic activity (CH 4 conversion ∼68%, CO 2 conversion ∼80%) and stability (>50 h with coking ≈0.022 mmol C·g cat –1 ·h –1 ) at 750 °C with a GHSV of 96,000 mL/(g cat ·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.