Solvent-free anchoring nano-sized zeolite on layered double hydroxide for highly selective transformation of syngas to gasoline-range hydrocarbons

Abstract

Nano-sized zeolites (NZs) were anchored on the layered double hydroxide consisting of cobalt and aluminum (Co-Al-LDH) using a solvent-free synthesis method (denoted as Co-Al-LDO-NZs). During the synthesis process, Co-Al-LDH was not only employed as a substrate for the growth of nano-sized zeolites but also acting as Al sources to participate in the formation of acid sites in the zeolite. The well-designed catalyst was used as a bifunctional catalyst for highly selective production of gasoline-range hydrocarbons from syngas through Fischer-Tropsch (FT) synthesis. Benefiting from the unique architecture of Co-Al-LDO-NZs, long-chain hydrocarbons formed on the active FT catalyst could diffuse to the zeolites surface, where hydrocracking and isomerization occurred. Furthermore, different from the traditional zeolite-supported FT catalyst, the nanoscale zeolite in Co-Al-LDO-NZs efficiently suppressed the over-cracking of hydrocarbons, lowering the selectivity of undesirable light hydrocarbons (CH4 and C2–C4 alkanes).