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Objective It is to research the problem that Mo/Al2 O3 catalyst is highly active for the reaction between H2S and CH4 to produce H2, but couldn't sustain a long term stability especially in a condition of high CH4 content. Methods Two kinds of Mo/Al2 O3 catalysts are compared in term of both H2S and CH4 reaction rates and H2 generation rate varying with reaction time on stream under the conditions of 0. 1 MPa, 800 °C, n ( H2S) n (CH4) = 1 5, and gas hourly space velocity of 20 000 Fr' ; and the various characterization and analysis techniques and methods are also used with SEM, XRD, HRTEM, BET, EA, TG, Raman and NH3-TPD/CO2-TPD. Results The Mo/Cluster Al2O3 catalyst prepared with the cluster structure Al203 as the supporter has a better catalytic activity and stability than the Mo/Com Al203 catalyst obtained with the commercial Al203 supporter. The H2 generation rate over the Mo/Cluster Al2O3 catalyst reached 8.4 mmol/(g • min) in the initial reaction stage, which was 3. 8 times of the Mo/Com Al203 catalyst, and the decrease after 20 h is significantly less than the former; It is found that although the Cluster Al2O, supporter possessed a lower specific surface area, the dispersion of active MoS2 particles supported on Cluster Al2O3 is better and can make MoS2 particles stabilized at high temperatures. Conclusions The reason could be assigned to the suitable acidic and alkaline strength and quantity distributions on the surface of Cluster Al203. Meanwhile, smaller-particle MoS2 has more edge-exposed active sites, which make Mo/Cluster Al2O3 catalyst perform more stable during the H2S/CH4 reforming reaction, and also can inhibit carbon deposition caused by CH4 cleavage to a certain extent. [ABSTRACT FROM AUTHOR]