Efficient Catalytic Combustion of Cyclohexane over PdAg/FeO Catalysts under Low-Temperature Conditions: Establishing the Degradation Mechanism Using PTR-TOF-MS and DRIFTS.

Cyclohexane, a typical volatile organic compound (VOC), poses high risks to the environment and humans. Herein, synthesized PdAg/FeO catalysts exhibited exceptional catalytic performance for cyclohexane combustion at lower temperatures (50% mineralization temperature () of 199 °C, 90% mineralization temperature () of 315 °C) than Pd/FeO ( of 262 °C, of 335 °C) and FeO ( of 305 °C, of 360 °C). In addition, PdAg/FeO displayed enhanced stability by alloying Ag with Pd. The redox and acidity of the PdAg/FeO were studied by XPS, H-TPR, and NH-TPD. diffuse reflectance infrared Fourier transform spectroscopy and proton-transfer-reaction time-of-flight mass spectrometry were applied to identify the intermediates formed on the catalyst surface and in the tail gas during oxidation, respectively. Results suggested that loading PdAg onto FeO significantly enhanced the adsorption and activation of oxygen and cyclohexane, oxidative dehydrogenation of cyclohexane to benzene, and catalytic cracking of cyclohexane to olefins at low temperatures. This in-depth study will benefit the design and application of efficient catalysts for the effective combustion of VOCs at low temperatures.