Boosting gas-phase radical reactions for efficient oxidative dehydrogenation of propane over boron-based macropore catalyst

Abstract

Efficiently boosting gas-phase radical reactions in the oxidative dehydrogenation of propane (ODHP) over boron-based catalysts requires the initiation, release, and propagation of radicals to work in a concerted manner within the catalytic system. To address this challenge, we developed a three-dimensional ordered macropore (3DOM) Al2O3 supported B2O3 catalyst. This unique design allows for the initiation, release, and propagation of radical reactions to take place within the macropore. By effectively balancing these processes, the designed catalyst demonstrated improved efficiency. The propane conversion over the B2O3/3DOM-Al2O3 catalyst with a pore size of 0.8 μm increased from 10 % to 25 % compared to that over the catalyst without the macropore. We attribute this enhancement to the ability of the 3DOM structure to facilitate the quick release of radicals from the B2O3 on the macropore surface into the same or nearby macropore within the 3DOM support. This efficient release of radicals minimizes the quenching losses that typically occur during the release process and ensures their efficient utilization in subsequent gas-phase radical reactions. This discovery offers a promising way for the development and optimization of boron-based catalysts for ODH of alkane.