Catalytic syngas conversion is the key route to bridge the gap between various carbon resources and essential chemicals. Oxide-zeolite (OXZEO) bifunctional catalysis is a new platform for this conversion, showing great potential for further industrialization.
However, the in-depth understanding of the structure-activity relationship of the catalysts-reaction, especially on oxide component is still unclear.
Recently, a research team led by Prof. HOU Guangjin from the State Key Laboratory of Catalysis(SKLC) has revealed the synergistic interplay mechanism of dual active sites on bimetallic oxide for efficient syngas conversion at atomic level.
This study was published in Chem on Feb. 8.
Revealing the synergistic interplay of dual active sites on a spinel ZnAl2O4 bimetallic oxide for syngas conversion by state-of-the-art solid-state NMR technologies (Image by HAN Qiao and GAO Pan)
The researchers investigated syngas conversion over a representative spinel ZnAl2O4 oxide with combined advanced solid-state nuclear magnetic resonance (NMR) technologies. They utilized in-situ NMR method to observe the full process of syngas conversion to methanol over ZnAl2O4 catalyst, during which the formate and methoxy species were identified as the key intermediates.
Through a series of double resonance and multi-dimensional correlation NMR experiments, they identified the dual active sites with structure of -AlIV-OH···ZnIII-. Thus, they proposed the synergistic catalytic mechanism of the dual active sites on ZnAl2O4 catalyst for syngas conversion reaction.
Moreover, they elaborated the dynamic evolution of the reaction intermediates and active sites during the reaction process at atomic level.
"On one hand, our work exemplifies the increasing capability of solid-state NMR spectroscopy in the study of surface/interface catalysis," Prof. HOU said. "On the other hand, the current understanding of the active sites and reaction mechanism can bring inspiration to study syngas conversion and CO2 hydrogenation on other bimetallic oxide systems, providing important guidance for the rational design and modulation of high-efficiency oxide catalysts."
The study was supported by the National Key R&D Programme of China, the National Natural Science Foundation of China, the Liaoning Revitalization Talents Program, the China National Postdoctoral Program for Innovative Talents, the China Postdoctoral Science Foundation, and the DICP funding.
