Highly effective microwave catalytic direct decomposition of H2S over carbon encapsulated Mo2C–Co2C/SiC composite.

The direct decomposition of H 2 S into CO x -free H 2 and S is an attractive approach in respect of both environmental and energy advantages. However, to achieve the highly effective direct H 2 S decomposition reaction is a critical scientific challenge, owning to the serious thermal equilibrium limitation in this reaction. Herein, we develop carbon encapsulated Mo 2 C–Co 2 C/SiC composite (Mo 2 C–Co 2 C/SiC@C) via in-situ microwave carbonization, as a novel microwave catalyst for highly effective direct decomposition of H 2 S into CO x -free H 2 and S by microwave catalysis. Significantly, the H 2 S conversion is impressively up to 90.3% at 750 °C over Mo 2 C–Co 2 C/SiC@C microwave catalyst in the microwave catalytic reaction mode, which greatly surpasses the corresponding H 2 S equilibrium conversion in the conventional reaction mode. Importantly, Mo 2 C–Co 2 C/SiC@C exhibits outstanding stability under microwave irradiation. It is found that microwave catalysis can break the chemical equilibrium limitation of the H 2 S decomposition reaction, which displays a significant microwave selective catalytic effect. This work provides a novel route for high value utilization of toxic and abundant H 2 S resources, and thus opens a new approach for the design of high active and stable microwave catalysts in microwave catalytic reactions. Image 1 • H 2 S conversion is highly up to 90.3% at 750 °C under microwave irradiation. • Mo 2 C–Co 2 C/SiC@C successfully prepared via a novel in-situ microwave carbonization. • Mo 2 C–Co 2 C/SiC@C is high active and stable for H 2 S decomposition in the MCRM. • Catalytic activity in the MCRM is much higher than that in the CRM. • Microwave irradiation can break chemical equilibrium of H 2 S decomposition reaction. [ABSTRACT FROM AUTHOR]