Catalytic dehydrogenation of propane by electrospinning one-dimensional Zn-Ga2O3-Al2O3 nanofibres under CO2 atmosphere

• ZnO-Ga 2 O 3 -Al 2 O 3 nanofibers prepared by electrospinning feature a large specific surface area , multilevel pore structure , anti-coking properties, and enhanced stability. • The increased specific surface area and Zn/Ga doping deepen the Al 2 O 3 lattice, reducing crystallinity , creating more surface defects , and enhancing reactivity. • Zn addition increased surface acidity , reduced propane C–H activation energy , and generated more low-coordinated Ga 3+ ions. CO 2 lowered the dehydrogenation activation barrier on ZnO, speeding up the reaction. CO 2 oxidative dehydrogenation of propane (CO 2 -ODHP) is currently a prominent research focus, as it enables the conversion of propane to propylene while facilitating the resource-efficient utilization of CO 2 . Gallium-based catalysts are regarded as among the most promising candidates owing to their superior dehydrogenation activity. However, their intrinsic vulnerability to coking at high temperatures and low CO 2 utilization efficiency during the reaction process have constrained their development. The superior activation capability of Zn for CO 2 further promotes the reaction. The catalysts prepared via the electrospinning method exhibit a large specific surface area and a hierarchical pore structure , which significantly enhance the mass transfer rate while effectively suppressing coking. In this study, ZnO-Ga 2 O 3 -Al 2 O 3 mixed oxides with varying molar ratios were synthesized through electrospinning for CO 2 -ODHP. At 500 °C, the propane conversion reached 57.5 %, with a propylene selectivity of 94.2 %. Notably, at 400 °C, the propane conversion was still 2.2 %, accompanied by an exceptionally high propylene selectivity of 99.8 %. Lowering the reaction temperature effectively inhibited coking. The characterization results demonstrated that the one-dimensional nanostructures fabricated via the electrospinning method exhibited a much larger specific surface area. Their distinctive multilevel pore structure facilitated enhanced mass transfer and accelerated the conversion of reaction intermediates, thereby reducing catalyst coking and improving stability. Meanwhile, the doping of Zn in the catalyst not only regulates its pH but also increases the formation of low-coordinated Ga 3+ ions. Additionally, the presence of CO 2 facilitates the desorption of hydrogen from the ZnO surface, thereby enhancing the overall catalytic activity. The in situ infrared results revealed that the reaction mechanism involved a two-step dehydrogenation process via isobaric cleavage of propane.