Co-Al nanosheets derived from LDHs and their catalytic performance for syngas conversion.

Layered double hydroxides (LDHs) were innovatively employed in this study as catalyst for synthesis gas conversion to chemicals, such as oxygenates. Cobalt-aluminium layered double hydroxides (Co-Al LDHs) was prepared at different temperatures. and lactate was successfully intercalated into the LDHs by ion-exchange method and then the material was further delaminated in water at ambient temperature. The samples were characterized by SEM, TEM and AFM, and separately dispersed nanosheets can be clearly observed. The prepared lamellas were applied in aqueous-phase synthesis gas conversion reaction. The catalysts generated a superior activity of 0.055-0.675 mol·mol·h and greater oxygenated product (acetaldehyde) selectivity (S = 75-88%) than conventional cobalt Fisher-Tropsch (FT) synthesis catalysts. Ammonium ion showed some effect of the selectivity of the acetaldehyde. The original research results suggested a promising application of the mono-dispersed ultrathin cobalt-bearing LDHs nanosheets in the aqueous phase syngas conversion to valuable oxygenate products.