Highly effective microwave catalytic direct decomposition of H2S into H2 and S over MeS-based (Me=Ni,Co) microwave catalysts

[Display omitted] •H2S conversion is highly up to 80.33% at 788°C under microwave irradiation.•Catalytic activity in the MCRM is much higher than that in the CRM.•Microwave irradiation can break chemical equilibrium of H2S decomposition reaction.•Microwave irradiation exhibits the selective catalytic effect. The direct decomposition of H2S into H2 and S has attracted increasing attention because it can simultaneously recover valuable H2 and elemental sulfur from a highly toxic waste gas. However, the thermal equilibrium limitation in this reaction presents a challenge to direct decomposition of H2S with high efficiency. Here we present a highly effective approach for direct decomposition of H2S into H2 and S that can be achieved by microwave catalysis over MeS-based (Me=Ni,Co) microwave catalysts. These catalysts display outstanding activity with H2S conversion respectively up to 80.33% for the CoS/γ-Al2O3/BaMn0.2Cu0.8O3 at 788°C and 44.98% for NiS/γ-Al2O3/BaMn0.2Cu0.8O3 at 650°C under microwave irradiation, which remarkably exceeds the corresponding H2S equilibrium conversion at the conventional reaction condition. It is found that microwave irradiation exhibited the selective catalytic effect, which can break the chemical equilibrium of H2S decomposition reaction over MeS-based (Me=Ni,Co) microwave catalysts under microwave irradiation.