In the present work, the H2S adsorption performance of several activated carbon-based sorbents was studied using the temperature program adsorption technique under the temperature range of 30 degrees-550 degrees C. The activated carbons applied in this study include (i) commercial-grade activated carbon, (ii) the commercial-grade activated carbon modified by steam activation to enhance higher specific surface area, and (iii) the activated carbon impregnated with alkaline compounds (i.e., NaOH and Na2CO3). It was found that the impregnation of activated carbon with NaOH and Na2CO3 can efficiently promote the H2S adsorption capacity of activated carbon in the range of temperatures studied. At 30 degrees C, the Na2CO3-impregnated sample showed better adsorption capacity than the NaOH-impregnated sample, whereas their adsorption performance was almost identical at higher adsorption temperatures. Interestingly, although the activated carbon modified by steam activation showed better surface properties than commercial-grade activated carbon, its H2S adsorption capacities were relatively lower. This could be due to the loss of potassium from activated carbon during the modification by steam activation.