Highly Efficient CO2 to CO Transformation over Cu-Based Catalyst Derived from a CuMgAl-Layered Double Hydroxide (LDH)

Supported Cu-based catalysts are promising catalysts for RWGS reactions. Herein, CuMgAl-LDHs (LDHs: Layered double hydroxides) were used as the precursors to obtain supported Cu with good dispersion and high stability. The reduction of CuMgAl-LDH at 400 degrees C led to the formation of 0.3CuMgAl-LDH-400, with Cu nanoparticles well dispersed on MgO/Al2O3, which exhibited superior activity and high stability for RWGS. 33.5 % of CO2 was converted, with selectivity of almost 100 % to CO at 350 degrees C under a high space velocity, among the highest for RWGS ever reported for Cu-based catalysts, especially at a low reaction temperature. In-situ DRIFTS and CO2-TPD revealed that its superior performance is attributed to high Cu dispersion which is beneficial for the dissociation of H-2, as well as the presence of variety of basic sites for adsorption towards CO2 to facilitate the formation of formates. This study demonstrates the great opportunity of LDHs in the preparations of supported metal-based catalysts.