Highly effective direct decomposition of H2S into H2 and S by microwave catalysis over CoS-MoS2/γ-Al2O3 microwave catalysts

•H2S conversion is up to 66.9% for CoS-MoS2/γ-Al2O3 at 750 °C in the MCRM.•Ea′ for CoS-MoS2/γ-Al2O3 is as low as 17.46 kJ/mol under microwave irradiation.•Microwave irradiation can break chemical equilibrium of H2S decomposition reaction.•Catalytic activity in the MCRM is much higher than that in the CRM.

Direct decomposition of H2S into H2 and S has attracted increasing attention because it can simultaneously recover H2 and S from a hazardous waste gas. However, direct decomposition of H2S with high H2S conversion is still a great challenge. Herein, we report highly effective direct decomposition of H2S into H2 and S by microwave catalysis over CoS-MoS2/γ-Al2O3 microwave catalysts. The CoS-MoS2/γ-Al2O3 exhibits outstanding catalytic activity under microwave irradiation. The best H2S conversion is respectively up to 66.9% for CoS-MoS2/γ-Al2O3 and 36.2% for the MoS2/γ-Al2O3 catalyst at 750 °C under microwave irradiation, which greatly exceeds the corresponding H2S equilibrium conversion under the conventional thermal conditions. Importantly, the apparent activation energy for MoS2/γ-Al2O3 and CoS-MoS2/γ-Al2O3 microwave catalysts under microwave irradiation respectively decrease to as low as 20.74 and 17.46 kJ/mol, which displays an outstanding microwave direct catalytic effect. Our findings open a novel approach for the direct H2S decomposition reaction.

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