Synergistic interplay of dual active sites on spinel ZnAl2O4 for syngas conversion

The urgent need for efficiency improvement in the oxide-zeolite bifunctional syngas-to-hydrocarbon catalysis necessitates in-depth mechanistic insights into this reaction, especially for the initial syn- gas conversion over the oxide component, which remains poor. Herein, we comprehensively investigated syngas conversion over a representative ZnAl2O4 spinel oxide with state-of-the-art solid- state NMR technologies. Notably, specific surface dual active sites for syngas activation with-AlIV-OH center dot center dot center dot ZnIII- structure were unam- biguously identified. More importantly, the dynamic evolution of the reaction intermediates and active sites during the reaction pro- cess was elaborated at atomic level by a series of double resonance and multi-dimensional correlation NMR experiments. In combina- tion with in situ spectroscopic characterizations, we revealed the full cycle of the formate-methoxy-based pathway for the syngas- to-methanol conversion via synergistic interplay of the dual active sites. The in-depth atomic-level understanding of the catalytic mechanism will be beneficial to further rational design of high- performance catalysts for syngas conversion.

Automated summary

Efficiency improvement in the oxide-zeolite bifunctional syngas-to-hydrocarbon catalysis requires a deep understanding of the reaction mechanism, especially for the poor initial syn-gas conversion over the oxide component. Through advanced solid-state NMR technologies, specific surface dual active sites for syngas activation were identified, and the dynamic evolution of reaction intermediates and active sites during the reaction process were elucidated at the atomic level. The in-depth understanding of the catalytic mechanism will aid in the rational design of high-performance catalysts for syngas conversion.