Oxidative conversion of cyclohexane to olefins on hexagonal boron nitride

Abstract

The oxidative conversion of cyclohexane (OCC) to valuable olefins presents an innovative strategy for efficient utilization, overcoming its inherent resistance to traditional cracking methods. This study demonstrates the superior performance of hexagonal boron nitride (h-BN) in OCC, especially mitigating deep oxidation and dehydrogenation to achieve high olefin selectivity. At 550°C, with 32.5 % cyclohexane conversion, cyclohexene selectivity reaches 49.1 % and open-ring alkenes account for 20.1 %. The reaction is driven by gas-phase free radical mechanism, where higher reaction temperature and alkyl-oxygen ratio favor forming open-ring alkenes while maintaining high cyclohexene selectivity. The weak adsorption of olefins on h-BN and the suppression of deep oxidation and dehydrogenation through radical-mediated pathways are crucial for its exceptional performance. This approach effectively minimizes further oxidation and dehydrogenation of radicals and olefins, enhancing olefin selectivity. These findings provide a promising pathway for efficient cyclohexane utilization and advance the understanding of h-BN’s catalytic role in alkane oxidation process.