Florou Alexandra, Bampos Georgios, Natsi Panagiota D, Kokka Aliki, Panagiotopoulou Paraskevi
Laboratory of Environmental Catalysis, School of Chemical and Environmental Engineering, Technical University of Crete, GR-73100 Chania, Greece.
Department of Chemical Engineering, University of Patras, GR-26504 Patras, Greece.
Nanomaterials (Basel). 2025 Jul 2;15(13):1029. doi: 10.3390/nano15131029.
Propylene production through the CO-assisted oxidative dehydrogenation of propane (CO-ODP) is an effective route able to address the ever-increasing demand for propylene and simultaneously utilize CO. In this study, a series of alumina-supported gallium oxide catalysts of variable GaO loading was synthesized, characterized, and evaluated with respect to their activity for the CO-ODP reaction. It was found that both the catalysts' physicochemical characteristics and performance were strongly affected by the amount of GaO dispersed on AlO. Surface basicity was maximized for the sample containing 20 wt.% GaO, whereas surface acidity was monotonically increased with increasing GaO loading. A volcano-type correlation was found between catalytic performance and acid/base properties, according to which propane conversion and propylene yield exhibited optimum values for intermediate surface basicity and acidity, which both correspond to the sample containing 30 wt.% GaO. The dispersion of a suitable amount of GaO on the AlO surface not only enhances the conversion of propane to propylene but also suppresses the formation of side products (CH, CH, and CH) at temperatures of practical interest. The 30%GaO-AlO catalyst exhibited very good stability at 550 °C, where byproduct formation and carbon deposition were limited. Mechanistic studies indicated that the reaction proceeds through a two-step oxidative route with the participation of CO in the abstraction of H, originating from propane dehydrogenation, through the reverse water-gas reaction (RWGS) reaction, shifting the thermodynamic equilibrium towards propylene generation.
通过丙烷的CO辅助氧化脱氢（CO-ODP）生产丙烯是一种有效的途径，能够满足对丙烯不断增长的需求，同时利用CO。在本研究中，合成了一系列具有可变GaO负载量的氧化铝负载氧化镓催化剂，对其进行了表征，并评估了它们对CO-ODP反应的活性。发现催化剂的物理化学特性和性能都受到分散在AlO上的GaO量的强烈影响。对于含有20 wt.% GaO的样品，表面碱度达到最大值，而表面酸度随着GaO负载量的增加而单调增加。在催化性能和酸碱性质之间发现了一种火山型相关性，据此丙烷转化率和丙烯产率在中间表面碱度和酸度时表现出最佳值，这两者都对应于含有30 wt.% GaO的样品。在AlO表面分散适量的GaO不仅提高了丙烷向丙烯的转化率，而且在实际感兴趣的温度下抑制了副产物（CH、CH和CH）的形成。30%GaO-AlO催化剂在550℃下表现出非常好的稳定性，此时副产物形成和碳沉积受到限制。机理研究表明，该反应通过两步氧化途径进行，CO参与了丙烷脱氢产生的H的夺取，通过逆水煤气变换（RWGS）反应，将热力学平衡向丙烯生成方向移动。
