Anti-Coking Performance of Ethyl Benzene Pyrolysis of Silicon-Based Films Prepared through Plasma-Enhanced Chemical Vapour Deposition

Non-metal thin films have received considerable attention because they can shield Fe and Ni elements from metal catalytic coking. In this study, the SiF 4 –H 2 –Ar mixture gas was used as the silicon source to deposit silicon-based films on 316 stainless steel wafer substrates through plasma-enhanced chemical vapour deposition (PECVD). The morphology, element composition, and crystalline fraction of the substrates were characterised through scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The optimal preparation temperature for surface silicon-based thin films was 300 °C (uniformly inlaid without cracks). Ethyl benzene was used at 700–900 °C (ΔT = 50 °C) and normal pressure to evaluate the performance of silicon-based thin films in inhibiting metal-catalytic coking. The temperature programmed oxidation-infrared absorption results showed that the coking inhibition rate of silicon-based thin films at T ≤ 800 °C was 70%, and when T > 800 °C, the coking inhibition rate decreases rapidly. The coke on the surface of the silicon-based films had a more lower degree of graphitization than that on the monocrystalline silicon(111) wafer and quartz wafer.