Highly Active Ni–Ru Bimetallic Catalyst Integrated with MFI Zeolite-Loaded Cerium Zirconium Oxide for Dry Reforming of Methane

Abstract

The dry reforming of methane (DRM) is a new potential technology that converts two major greenhouse gases into useful chemical feedstocks. The main challenge faced by this process is maintaining the catalyst with high catalytic activity and long-term stability. Here, a simple and effective preparation route for the synthesis of functional nanomolecular sieve catalysts (NiRu x CZZ5) from kaolinite tailings was developed for dry reforming of methane with CO 2 . The silica monoliths with flower-like spherical and micropore structures (ZSM-5) were prepared by crystal growth method, and the metal components were loaded by ultrasonic-assisted impregnation method. The NiRu 0.5 CZZ5 catalyst exhibited excellent catalytic performance (maxmium CO 2 and CH 4 conversions up to 100 and 95.6%, respectively) and very good stability (up to 100h). The interfacial confinement and the strong support interaction are principally responsible for the excellent catalytic activity of the catalyst. The in situ DRIFTS was used to elucidate the possible carbon conversion steps, and stable surface intermediates were also identified.

Noble Metals in Recent Developments of Heterogeneous Catalysts for CO2Conversion Processes

“…The authors found that the sturdy SiO 2 ‐Ru interaction, along with the confinement effect of the silica shells, which hampered Ru migration, decreased the gathering of Ru particles at the high reaction temperature (700 °C), also inhibiting carbon generation. Miao and co‐workers [268] reached an outstanding catalytic activity and stability (at 800 °C and GHSV of 60,000), over 100 h of reaction, with initial CO 2 and CH 4 conversions of 100 % and 100 %, and final CO 2 and CH 4 conversions of 78 % and 68.8 %, respectively, using a NiRu x CZZ5 catalyst, composed by a flower‐like spherical ZSM‐5 zeolite with metal components loaded by ultrasonic‐assisted impregnation method. Beyond the ability of Ru atoms to slow down CH 4 dissociation and increase C* oxidation, such findings accounted for the interfacial confinement of microporous molecular sieves and the strong metal‐support interaction guaranteed by the unique morphology of the ZSM‐5 zeolite, providing high sintering resistance.…”

Extraordinary Catalytic Performance of Nickel Half‐Metal Clusters for Light‐Driven Dry Reforming of Methane

“…[ 1 ] DRM has been regarded as a promising route to tackle excess greenhouse gas emissions as it converts the two greenhouse gases of CO 2 and CH 4 to syngas (H 2 and CO), a key chemical feedstock for large‐scale industrial processes to produce fuels, high‐value‐added chemicals, and clean hydrogen energy. [ 2–26 ] However, there are two major obstacles to this scenario. One is high energy consumption for DRM as it is a highly endothermic reaction (Δ H 298 = 247 kJ mol −1 ), requiring a high reaction temperature (usually above 700 °C).…”

“…[ 2–6,27–46 ] Intensive studies have identified metallic Ni‐based catalysts as the most promising candidate for both conventional thermocatalytic and light‐driven catalytic DRM owing to their earth‐abundance, inexpensiveness, and high initial activity comparable to precious metal catalysts. [ 9–14,18–34 ] However, they are vulnerable to deactivation due to severe coking, blocking their widely practical application. As the side reactions of coking are thermodynamically unavoidable, [ 12,13 ] the key issue of the catalyst deactivation could only be tackled through rationally designing unique Ni‐based catalysts that could kinetically inhibit coking.…”

“…[2][3][4][5][6][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] Intensive studies have identified metallic Ni-based catalysts as the most promising candidate for both conventional thermocatalytic and lightdriven catalytic DRM owing to their earth-abundance, inexpensiveness, and high initial activity comparable to precious metal catalysts. [9][10][11][12][13][14][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] However, they are vulnerable to deactivation due to severe coking, blocking their widely practical application. As the side reactions of coking are thermodynamically unavoidable,...…”

Zeolites Boost the Reactivity of Chemical Looping by Brønsted Acid Sites

“…Cheng et al explored that the strong acid sites on ZSM-5 facilitated the conversion of syngas to aromatics, but too strong Brønsted acidity can lead to side reactions that reduce the selectivity of aromatics. Moreover, the strong support interaction and reduced carbon deposition contributed mainly to the improved catalytic activity. , …”