Improving catalytic performance via induction heating: selective oxidation of H2S on a nitrogen-doped carbon catalyst as a model reaction

Abstract

In this work, a macroscopic nitrogen-doped mesoporous carbon-coated silicon carbide catalyst (NMC/SiC) was developed and fully evaluated as a metal-free catalyst for the selective oxidation of H₂S into elemental sulfur under various conditions using both noncontact induction heating (IH) and classical Joule heating (JH) modes. The results obtained indicated that the coated SiC catalyst exhibited excellent desulfurization performance when operated with induction heating. Indeed, when operated with IH, the catalyst displays better desulfurization performance under challenging reaction conditions, i.e., a low reaction temperature of 180 °C and a high gaseous space velocity of 3600 h⁻¹, than when operated using the indirect convection/conduction JH mode. The high desulfurization performance was attributed to the highly effective heat management inside the catalyst bed via an IH along with a short diffusion length associated with the nanoscopic dimension of the nitrogen-doped carbon coating layer on the macroscopic silicon carbide host substrate. The catalyst also displays high stability as a function of time on stream thanks to the high stability and activity of nitrogen sites.