More carbon surrounding the iron particles was ablated due to the acceleration effect of ferrite to the water vapor-carbon reaction, which generated mesopores.

• 单质铁对炭-水反应有催化气化作用。在活化阶段，铁粒子周围的炭基体与水蒸汽的活化反应速率快，被刻蚀掉更多的炭，所以在其周围形成中孔。