Dry Reforming of Methane with Suppressed Carbon Deposition over Cr- and Ni-Loaded Dealuminated β Zeolites

Abstract

Dry reforming of methane (DRM) is an endothermic reaction that consumes energy during operation. In Ni-based catalysts, carbon produced by side reactions leads to catalyst deactivation and damage to the reactor tube. We have developed a catalyst that maintains its activity and suppresses carbon deposition at a low temperature (873 K). New catalysts were synthesized by loading Cr and Ni onto dealuminated β zeolites. The peak shifts in the X-ray diffraction (XRD) measurements suggested that the introduced Cr and Ni species interacted with the zeolite framework. UV−vis spectra showed that the loaded Cr interacted with the zeolite was present as Cr 6+ . The synthesized catalysts were applied to the DRM reaction. As a result, the Cr-loaded catalysts had lower carbon deposition than only the Ni-loaded catalyst. The Cr species mainly contributed to the suppression of the methane decomposition reaction, leading to a much lower coke deposition and a more selective DRM reaction. This study provides a new strategy for catalyst design to suppress coke deposition and selective DRM reactions.

Review and Outlook of Confined Ni Catalysts for the Dry Reforming of Methane Reaction

“…This would increase the sintering resistance of the metal species at high temperatures. Besides, the hierarchical zeolites have high capacities for molecular adsorption, which would accelerate the transformation rates of reactants. − Currently, zeolites, such as SBA-15, MCM-41, ZSM-5, etc., are reported to accommodate Ni nanoparticles for DRM.…”

Smart Designs of Zeolite-Based Catalysts for Dry Reforming of Methane: A Review

“…Syngas as a mixture of CO and H 2 has been efficiently utilized as a fuel or converted into other products. In particular, after a downstream processing (such as membrane separation or Fischer–Tropsch synthesis), pure H 2 and other value-added products could be formed. − The reactions to generate syngas mainly include reforming of natural gases and tars. − Among the various natural gas and tar molecules, CH 4 is featured with the high content of hydrogen, easy production, and large abundance, widely used as the raw feed in reforming reactions (Figure ), like steam reforming of methane (SRM), − dry reforming of methane (DRM), − and partial oxidation of methane (POM). − Therein, the SRM process is an industrially mature process and featured with a H 2 -rich syngas production; the downstream purification step can also be reduced due to the simultaneous Water–Gas Shift Reaction. − As the main products, the H 2 -abundant fuel stream suits the polymer electrolyte membrane fuel cells, which are more efficient than combustion engines. But it requires high energy to generate steam, and the catalyst suffers from sulfur poisoning .…”