Development of core–shell structured Mo2C@BN as novel microwave catalysts for highly effective direct decomposition of H2S into H2 and S at low temperature

Abstract

Direct decomposition of hydrogen sulfide is an attractive approach for producing CO_x-free H₂ and S from a toxic and abundant waste gas. However, the direct decomposition of H₂S into H₂ and S with high efficiency at low temperature remains a challenge, due to the thermodynamic equilibrium constraints. Herein, we developed core–shell structured Mo₂C@BN as novel microwave catalysts for highly effective direct decomposition of H₂S into H₂ and S. Interestingly, the calcination temperature of the Mo₂C@BN microwave catalysts has a great influence on the catalytic performance. Importantly, the Mo₂C@BN-1000 catalyst displays high catalytic activity at low temperature in the microwave catalytic reaction mode with the H₂S conversion impressively reaching up to 99.9% at 650 °C, which remarkably surpasses the corresponding H₂S equilibrium conversion in the conventional reaction mode. This indicates that the equilibrium of direct H₂S decomposition is broken in the microwave catalytic reaction mode, which shows the microwave selective catalytic effect. This work provides an alternative avenue for the high value utilization of toxic and abundant H₂S resources, and opens a novel approach for highly effective direct decomposition of H₂S into CO_x-free H₂ and S at low temperature.