LaAlO3-Tailored Active Pairs of Co0–Coδ+ Supported on ZrO2 for Higher Alcohol Synthesis from Syngas

Cobalt-based catalysts are promising for converting syngas (CO + H2) into higher alcohols, where Coδ+/Co0 is the active pair for higher alcohol formation. The challenge lies in how to construct and to adjust the active pair. In this work, the active pair of Coδ+/Co0 can be obtained via the interaction between a metal Co nanoparticle (NP) with LaAlO3. A series of LaAl1–xCoxO3 (x = 0.2–0.5) were supported on ZrO2 according to the wet-impregnation method with citric acid as the complexing agent, and after reduction, the catalyst of Co–LaAlO3/ZrO2 could be obtained, where cobalt was in the state of Coδ+/Co0, which is the active pair. Coδ+ was formed at the interfaces between Co NPs and LaAlO3 owing to the interaction between them, and the Coδ+/Co0 ratio could be adjusted by the size of Co NPs. In Coδ+/Co0, Coδ+ could adsorb associatively CO and Co0 could adsorb dissociatively, which catalyzed syngas to higher alcohols synergistically. By the way, there is an electron transformation between Co and LaAlO3, which could improve the activity.