Constructing Molybdenum-Stabilized Nickel-Oxo Sites for Boosting Low-Temperature Dry Reforming of Methane

Dry reforming of methane (DRM) converts methane (CH4) and carbon dioxide (CO2) into syngas (H2 and CO), which serves as a crucial feedstock for the production of high-value chemicals. However, traditional DRM requires high temperatures (>800 °C) to effectively activate the C–H and C=O bonds, resulting in significant energy demands. Herein, we present a NiMo/MgO catalyst to promote DRM reactions at significantly lower temperatures (465 °C). Molybdenum stabilizes nickel-oxo species within surface chemistry that lower the energy required for bond dissociation, enabling efficient DRM at reduced temperatures. Using in situ steady-state isotopic transient kinetic analysis (SSITKA), Fourier transform diffuse reflectance infrared spectroscopy (DRIFTS), and isotopic analysis (13CO2–CD4), we identified the formation rate of hydroxymethyl groups involving C–H bonds to preferentially occur before the dehydrogenation process, thereby efficiently regulating the aggregation of hydroxyl groups dissociated during CO2 hydrogenation on the surface. Results showed specific yield rates of 2.49 mmol g cat–1 min–1 for H2 and 2.34 mmol g cat–1 min–1 for CO at 465 °C. These results demonstrate that the “hydroxyl-mediated” DRM mechanism operating at mild temperatures is effective in enhancing syngas production. This research provides insights into low-temperature DRM kinetics and catalyst design for enhanced energy efficiency.