Effect of straw addition to coal on coal-based activated carbon for methane decomposition

Activated carbon (AC) is a promising catalyst for methane decomposition due to low cost, easy modification of its properties and high temperature resistance. The carbon source will affect the properties of the resultant AC and its catalytic performance in methane decomposition. In this paper, Buliangou (BLG) coal combined with biomass straw was used as the carbon precursor to prepare AC at 850 oC by KOH activation. The effect of straw addition amount to coal on the pore structure, surface chemistry of the prepared AC and its catalytic performance on methane decomposition was investigated. The result of thermo-gravimetric analysis showed that the addition of straw promoted coal pyrolysis, but the promotion was weakened as the amount of biomass straw increases. The addition of straw obviously benefits the mesoporous development of AC. the total specific surface area and pore volume of AC first increase and then decrease with the increase of straw amount. When the mass ratio of BLG coal and straw is 1:1, the resultant AC has the largest specific surface area and pore volume, and higher activity and better stability in the methane decomposition. Higher mesoporosity is the main reason for the better catalytic performance of AC in methane decomposition to hydrogen.