Highly Dispersed Ni–Fe Alloy Catalysts on MgAl2O4 Derived from Hydrotalcite for Direct Ethanol Synthesis from Syngas

Abstract

In view of the dual active sites mechanism of direct ethanol synthesis and the excellent catalytic performance of bimetallic catalysts, a series of Ni–Fe alloy catalysts with different Ni/Fe molar ratios derived from layered double hydroxides (LDHs) precursors are synthesized. During the calcination and reduction process of LDHs precursors, the Ni–Fe alloy is obtained, and attributed to all the elements being evenly dispersed at the atomic level in the LDHs precursors; meanwhile, a strong interaction between Ni–Fe alloy and MgAl2O4 support exists. As a result, Ni–Fe alloy nanoparticles are highly dispersed on the MgAl2O4 surface. The high CO adsorption ability on the Ni–Fe alloy and synergism catalysis between Ni and Fe result in excellent catalytic activity and high selectivity to ethanol on the bimetallic Ni–Fe alloy. In addition, the strong antisintering ability and stable alloy structure bring about a good catalytic stability. This research proposes a new catalytic system for direct ethanol synthesis from syngas.