(459h) Design of Anti-Coking and Anti-Sintering Ni/Mxene Catalyst for Dry Reforming of Methane

Dry reforming of methane (DRM) is a reaction that utilizes two greenhouse gases (CH₄ and CO₂) to produce syngas (a mixture of H₂ and CO). For DRM to be employed on an industrial scale, an efficient catalyst-support system needs to be designed, and a solution is currently elusive due to severe coking and sintering of the catalysts. MXenes are a new family of layered and porous two-dimensional materials with exceptional properties that can be harnessed to address the limitations of DRM catalysts. In this work, we investigate the use of Ti₄N₃T_x MXene as a support for Ni catalysts in DRM. Ti₄N₃T_x is of interest due to its layered structure, which allows the catalyst to be intercalated with the sheets and anchored for reduced sintering; more importantly, its highly electrophilic properties are expected to also facilitate rapid oxygen spillover, thereby reducing coking. The MAX phase (Ti₄AlN₃) is etched using a concentrated solution of LiF in HCl and intercalated using Ni(NO₃)₂.6H₂O. The solid is centrifuged, vacuum dried, and annealed to produce Ni/Ti₄N₃T_x. The catalyst is characterized using a variety of techniques, including electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, temperature-programmed reduction, and Raman spectroscopy. DRM catalytic performance is evaluated at 700°C using a feed ratio of CH₄/CO₂ of 1:1 and a high space velocity (180,000 ml/g_cat.hr). Ni nanoparticles anchored inside sheets of the layered support are expected to achieve both sintering and coking resistance simultaneously. Using this approach, we can limit sintering and coking and take a major step toward obtaining an industrial catalyst for DRM.