As a sustainable, environmentally friendly, and economically viable way to produce 1,3-butadiene, the ethanol-to-butadiene (ETB) process has received increasing attention recently. This ETB process normally requires catalysts with suitable acidity and basicity, namely an acid–base balance. However, the origin of acid–base balance has not yet been elucidated. Herein, we demonstrate that by finely coordinating the interaction of ZnO and ZrO2, a butadiene productivity of 0.33 gBD gcat−1 h−1 at low WHSV and 1.39 gBD gcat−1 h−1 at high WHSV can be achieved. In contrast, pure ZnO prefers ethanol dehydrogenation to acetaldehyde and pure ZrO2 favors ethanol dehydration to ethylene and diethyl ether. Through a variety of characterization techniques, we found that the interaction of ZnO and ZrO2 alters the acidity and basicity of catalysts, resulting in volcanic shapes of ethanol conversion, butadiene selectivity, and butadiene yield in the ETB process. These findings provide in-depth insights into the understanding of the ETB process and may also apply to other reaction systems using ZnO–ZrO2 as catalytically active components.
The synthesis of SAPO-34 hollow fiber membranes employs the ball-milling assistant method to enhance membrane yield and quality. These membranes are then combined with CrO x /Al 2 O 3 catalyst to create a packed bed membrane reactor (PBMR) for propane dehydrogenation (PDH). The study investigates the impact of operating temperatures, weight hourly space velocities (WHSV), and sweep gas flow rates on the SAPO-34 zeolite membrane reactor's performance, comparing it to a traditional packed bed reactor (PBR). The removal of hydrogen from the reaction side significantly improves propane conversion, surpassing thermodynamic equilibrium. In PBMR, propylene selectivity slightly exceeds that in PBR, influenced by side reactions like hydrogenolysis and cracking after hydrogen removal. Furthermore, the SAPO-34 zeolite membrane reactor undergoes a prolonged stability test with frequent regeneration using pure propane as feedstock to simulate industrial conditions. It exhibits consistent performance over 120 regeneration cycles within 240 h, maintaining similar H 2 permeability and H 2 /C 3 H 8 selectivity as the fresh membrane post long-term testing.