H2 production from H2S over activated carbon prepared at different carbonization temperatures as efficient microwave catalyst

This study aims to prepare activated carbon (AC) using sawdust as a stable and active microwave catalyst for H2 production from H2S. The AC, including mesoporous, was prepared at different carbonization temperatures (AC1:800 °C, AC2:900 °C, AC3:1000 °C). AC3 exhibited the highest sp2/sp3 ratio, π-π∗ transitions and mesoporosity, facilitating efficient microwave interaction and resulting in more irradiation absorption. High and similar H2 production rates using AC1, AC2, and AC3 in the microwave-heated reactor (MWHR) were obtained at different reaction temperatures. The H2 production rate obtained with AC3 at average reaction temperatures of 700 °C, 800 °C, and 900 °C are 13, 14, and 18 mmolx10−3/min, respectively. However, the carbonization temperature played a crucial role in H2 production per the microwave energy absorption of catalysts in MWHR. This situation can be attributed to the formation of a high sp2/sp3 ratio and more π-π∗ transitions, which enhance microwave interaction. In the long-term activity test conducted with AC3 in MWHR, stable and efficient H2 production was achieved with 14 mmolx10−3/min at an average reaction temperature of.