Work

Methane Dry Reforming on N‐doped Carbon‐Supported Mo 2 C Catalysts: Impacts of N Functionality and Ni Addition

Year: 2025

Type: article

Abstract: Nitrogen‐doped carbon (NC)‐supported Mo and Ni–Mo catalysts were synthesized via pyrolysis and impregnation strategies to investigate their performance in methane dry reforming (DRM). By modulating nitrogen content (1.65–13.25 at.%) and speciation (pyridinic/pyrrolic versus graphitic N) in NC supports, we demonstrated that nitrogen functionalities critically influence MoO 2 reduction and Mo 2 C stabilization. Higher N content in NC 2 and NC 3 enhanced metal‐support interactions, promoting Mo 2 C formation during H 2 reduction, while NC 1 (low N) favored metallic Mo. However, under DRM conditions, all catalysts deactivated due to Mo 2 C oxidation to MoO 2 , with stability marginally improved at 850 °C via improved “oxidation‐re‐carbonization” cycles. Introducing Ni (5–15 wt.%) via impregnation facilitated CH 4 dissociation and lowered MoO 2 reduction temperatures through hydrogen spillover, boosting initial CH 4 /CO 2 conversions and H 2 /CO ratios. Yet, Ni incorporation accelerated carbon support degradation (>50% mass loss) and induced inactive phases (NiO, Ni 3 Mo 3 N), offsetting its promotional effects. Combined XRD, H 2 ‐TPR, Raman, and XPS analyses revealed the interplay between N defects, Mo speciation, and Ni–Mo interactions, underscoring the challenges in balancing activity and stability. This study highlights the dual role of nitrogen in stabilizing active phases and the limitations of Ni–Mo bifunctionality under oxidative DRM conditions, providing critical insights for designing robust, carbon‐supported catalysts through defect engineering and structural optimization.

Source: ChemCatChem

DOI: 10.1002/cctc.202500541