One-dimensional GaO-AlO nanofibers with unsaturated coordination Ga: Catalytic dehydrogenation of propane under CO atmosphere with excellent stability.

The pressing demand for propylene has spurred intensive research on the catalytic dehydrogenation of propane to produce propylene. Gallium-based catalysts are regarded as highly promising due to their exceptional dehydrogenation activity in the presence of CO. However, the inherent coking issue associated with high temperature reactions poses a constraint on the stability development of this process. In this study, we employed the electrospinning method to prepare a range of GaO-AlO mixed oxide one-dimensional nanofiber catalysts with varying molar ratios for CO oxidative dehydrogenation of propane (CO-OPDH). The propane conversion was up to 48.4 % and the propylene selectivity was high as 96.8 % at 500 °C, the ratio of propane to carbon dioxide is 1:2. After 100 h of reaction, the catalyst still maintains approximately 10 % conversion and exhibits a propylene selectivity of around 98 %. The electrospinning method produces one-dimensional nanostructures with a larger specific surface area, unique multi-stage pore structure and low-coordinated Ga, which enhances mass transfer and accelerates reaction intermediates. This results in less coking and improved catalyst stability. The high activity of the catalyst is attributed to an abundance of low-coordinated Ga ions associated with weak/medium-strong Lewis acid centers. In situ infrared analysis reveals that the reaction mechanism involves a two-step dehydrogenation via propane isocleavage, with the second dehydrogenation of Ga-OR at the metal-oxygen bond being the decisive speed step.