Co-tuning the content of hydroxyl nests and b-axis thickness of ZnOx/Silicalite-1 for efficient propane dehydrogenation

Tuning hydroxyl defects and constructing active sites at the molecular level is critical for rational design of propane dehydrogenation (PDH) catalysts and understanding the structure–activity relationship. For practical application, enhancing catalysts anti-coking performance is equally important. Herein, the simultaneous regulation of hydroxyl nests content and b -axis thickness was achieved by adjusting the urea/SiO 2 ratio during the preparation of Silicalite-1. The propylene formation rate of the catalysts prepared by introducing Zn species showed a linear positive correlation with the hydroxyl nests content, and the coking behavior was governed by the b -axis thickness of the support. The optimized ZnO x /Silicalite-1 exhibited a high propylene space time yield of 2.2 kg h −1 kg cat −1 with propane conversion of 31% at 550°C. This work provides novel insights into PDH catalyst design from both chemistry and chemical engineering views.