A strategy of constructing the Ni@silicalite-1 catalyst structure with high activity and resistance to sintering and carbon deposition for dry reforming of methane

Abstract

Dry reforming of methane (DRM) as a promising reaction has both benefits reducing greenhouse gasses’ emissions and producing syngas for Fischer-Tropsch synthesis, whereas the Ni based DRM catalysts significantly suffer from deactivation due to the problems of metal sintering and carbon deposition. This paper reports a strategy for preparing the Ni@silicalite-1 catalyst, with which the nickel metal was encapsulated into the silicalite-1 zeolite crystals as Ni nano-particles (Ni NPs) with much high dispersion. Being benefited from this special structure, the catalyst displayed much high activity and durability under ultra-high space velocity (GHSV = 900,000 mL⋅gcat−1⋅h−1) reaction conditions. The high durability of the catalyst is originated from the strong interaction of Ni with the support and the encapsulation of the composite in the zeolite framework, which made the catalyst highly resistant to sintering and coke deposition. The much high activity of the catalyst should be the result of that Ni was highly dispersed in the catalyst and channels of the zeolite provide pathway for the reactant molecules contacting the Ni NPs and for the product molecules releasing there.