Zeolites with incorporated Zn species are gaining relevance for catalyzing the dehydrogenation of short-chain alkanes. However, the presence of zinc also leads to the C-C cleavage in the alkane, lowering the selectivity to the olefin. We disclose herein the importance of controlling the zeolite particle size and the promoting role of K₂O addition to improve the alkene selectivity and catalyst stability during Zn-catalyzed CO₂-assisted oxidative dehydrogenation of ethane. In particular, the nano-sized SSZ-13 catalysts outperform the micro-sized SSZ-13 catalysts in terms of C₂H₆ conversion due to the critical role of zeolite crystal surface properties that improves the dispersion of the Zn phase. The modification of Zn with K₂O neutralizes the acidity of the catalysts, suppressing the formation of undesired paths and leading to higher C₂H₄ selectivity and improved stability. Detailed characterizations and density functional theory show that K₂O-neighbored (Zn-O-Zn)²⁺ lowers the activation barrier for the surface removal of H-based adsorbates. Overall, these findings demonstrate the roles of fine-tuning acid-base properties on the zeolite surface to control the catalytic performance during the CO₂-assisted conversion of light alkanes.

掺入 Zn 物质的沸石与催化短链烷烃的脱氢有关。然而，锌的存在也会导致烷烃中的 CC 裂解，从而降低对烯烃的选择性。我们在本文中公开了控制沸石粒度的重要性和K ₂ O添加的促进作用以在Zn催化的CO ₂辅助的乙烷氧化脱氢过程中改进烯烃选择性和催化剂稳定性。特别是，由于沸石晶体表面性质对改善 Zn 相分散的关键作用，纳米级 SSZ-13 催化剂在 C ₂ H ₆转化率方面优于微米级 SSZ-13 催化剂。K对Zn的改性₂ O 中和了催化剂的酸性，抑制了不希望的路径的形成，并导致更高的 C ₂ H ₄选择性和改进的稳定性。详细的表征和密度泛函理论表明，K ₂ O-neighbored (Zn-O-Zn) ²⁺降低了表面去除 H 基吸附物的活化势垒。总体而言，这些发现证明了微调沸石表面的酸碱性质在 CO ₂辅助的轻质烷烃转化过程中控制催化性能的作用。