High-Density Coordinatively Unsaturated Zn Catalyst for Efficient Alkane Dehydrogenation.

The exploration of non-noble metal catalysts for alkane dehydrogenation and their catalytic mechanisms is the priority in catalysis research. Here, we report a high-density coordinatively unsaturated Zn cation (Zn cus ) catalyst for the direct dehydrogenation (DDH) of ethylbenzene (EB) to styrene (ST). The catalyst demonstrated good catalytic performance (∼40% initial EB conversion rate and >98% ST selectivity) and excellent regeneration ability in the reaction, which is attributed to the high-density (HD) distribution and high-stability structure of Zn cus active sites on the surface of zinc silicate (HD-Zn cus @ZS). Density functional theory (DFT) calculations further illustrated the reaction pathway and intermediates, supporting that the Zn cus sites can efficiently activate the C-H bond of ethyl on ethylbenzene. Developing the high-density Zn cus catalyst and exploring the catalytic mechanism laid a good foundation for designing practical non-noble metal catalysts.