(521de) Design of Highly Stable Catalysts from MOF Template for Hydrogen Production in Dry Reforming of Methane

An effective way to mitigate the negative effect of greenhouse gas (GHG) emissions is by converting them to valuable products. Dry reforming of methane (DRM) is an effective technique that converts the primary GHGs, CO₂ and CH₄ to syngas (H₂+CO), facilitated by catalysts.

For decades, the focus on DRM is on catalyst development, the design of highly active and stable catalyst to combat the problem of coke formation that causes deactivation, especially when noble-metal catalysts (Ni, Co) were used. Therefore, materials like metal-organic framework (MOF) have gained attention in recent years for catalyst development. MOFs are highly porous materials composed of well-ordered structures of metal ions affixed by organic linkers. Due to their exceptional morphological characteristics, high surface area, flexible design, MOFs can serve as templates and precursors to design highly dispersed nano-porous materials.

In this work, a novel bimetallic Ni-Ce MOF-derived catalyst was synthesized via a facile solvothermal method, and the catalyst active site was activated under nitrogen atmosphere at 500⁰C for 2 h. Catalysts with varying nickel to ceria ratio were prepared, and their properties were determined via N₂ adsorption-desorption isotherms, X-ray diffraction, X-ray fluorescence, transmission electron microscopy, scanning electron microscopy, thermogravimetric analyzer, and hydrogen temperature programmed reduction analyses.

Results obtained showed high stability for all catalysts after 24 h and 120 h of DRM reaction at 700⁰C. Interestingly, catalyst containing 100% nickel without cerium exhibited great stability and CO₂ and CH₄ conversion of 80% and 68% respectively, with an average particle size of 10 nm. However, the addition of 60% cerium improved the catalyst performance. The average particle size reduced to 2 nm, H₂/CO ratio of 0.83 with negligible coke formed and CO₂ and CH₄ conversion of 87% and 75% respectively.

The results were convincing for the design of a highly stable catalyst for DRM process.