Effects of precursor phase distribution on the performance of Cu-based catalysts for direct CO2 conversion to dimethyl ether

Multifunctional Cu-based catalysts with various hydroxyl carbonates as precursors were prepared using hydrothermal and co-precipitation methods for direct catalytic hydrogenation of CO2 to dimethyl ether (DME). By regulating the variable composition and preparation method of the precursor, the phase distribution of the precursor is controlled, and then further affected the structure of the final catalysts. The C-CZA-HT-1/HZ catalyst with a mixture of hydrotalcite-like and aurichalcite precursors prepared by the hydrothermal method possesses uniform dispersion of Cu nanoparticles and excellent catalytic property. The optimized CO2 conversion was 27.6% with the highest DME yield of 12.9% for the C-CZA-HT-1/HZ catalyst. It disclosed that the appropriate Cu-ZnO interaction and oxygen vacancies can create excellent adsorption activation sites for the catalyst, which is essential for achieving high catalytic activity. Moreover, the adsorption and reaction intermediates were obtained by in-situ DRIFTS, and the results revealed that a large amount of formate intermediates could accelerate the conversion. The work provided deep insights into the design of excellent activity catalysts by using controllable hydrotalcite-containing precursors for CO2 catalytic hydrogenation to DME.