LDH-Derived (CuZn)<i>_x</i>Al<i>_y</i> Bifunctional Catalyst for Direct Synthesis of Dimethyl Ether from Syngas

Abstract

The direct synthesis of dimethyl ether (DME) from syngas can be realized by mixing a methanol synthesis catalyst and a methanol dehydration catalyst. Different from the general studies on mixture catalysts, herein, we presented a concise (CuZn)xAly catalyst derived from layered double hydroxides (LDHs) and investigated their catalytic performance for the direct synthesis of DME from syngas. The LDH precursors with different molar ratios of (CuZn)/Al were synthesized by a coprecipitation method. After calcination and reduction of LDH precursors, two types of catalytic components could be generated on the catalyst simultaneously and could perform dual catalytic actions for DME synthesis. The structure and catalytic performance of catalysts were greatly influenced by the ratio of (CuZn)/Al. When the ratio of (CuZn)/Al was 1:3, (CuZn)1Al3 presented the highest CO conversion and DME selectivity. The superior catalytic performance of (CuZn)1Al3 could be attributed to the synergic catalytic effect between well-dispersed Cu species and Al2O3.