摘要
采用溶胶-凝胶法(sol-gel)制备了一系列具有不同RuO_2含量的RuO_2-Fe_2O_3催化剂,并将其应用于氨选择性催化氧化(NH3-SCO)研究中。结果表明,所有RuO_2-Fe_2O_3催化剂都表现出较好的低温活性,且RuO_2含量对催化剂的NH3催化氧化活性影响显著。此外,利用BET、XRD、H2-TPR和DRIFTS等表征手段研究了催化剂的物理化学性质和催化活性之间的关系。结果表明,RuO_2的加入增大了催化剂的比表面积。RuO_2与Fe_2O_3之间存在的协同效应提高了催化剂的氧化还原能力,从而提高了催化剂的氨氧化活性。同时,RuO_2含量对催化剂表面酸性影响很大,且催化剂表面主要存在Lewis酸性位点。
A series of RuO_2-Fe_2O_3 catalysts varied in RuO_2 loading were prepared by sol-gel method and used for selective catalytic oxidation of ammonia to nitrogen. The results indicated that all the RuO_2-Fe_2O_3 catalysts showed an excellent low-temperature catalytic activity and the RuO_2 loading played a key role in catalytic activity of ammonia oxidation. Moreover,the characterizations of BET,XRD,H2-TPR and DRIFTS were employed to investigate the relation between the physicochemical property of catalysts and catalytic activity. The research results elucidated that the introduction of RuO_2 increased the surface area. The synergistic effect between RuO_2 and Fe_2O_3enhanced the redox property and the catalytic activity of ammonia oxidation. Meanwhile,the RuO_2 loading gave the significant effect on surface acidity of catalysts. Lewis acid sites were predominant on the catalyst surface.
引文
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