Catalytic wet air oxidation of aqueous ammonia with activated carbon
Catalytic wet air oxidation of aqueous ammonia with activated carbon
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DOI：
10.1016/s0926-3373(03)00229-7
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发表时间：
2003-11
影响因子：
22.1
通讯作者：
Croswel Aguilar;Rafael García;G. Soto-Garrido;R. Arriagada
中科院分区：
文献类型：
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作者：
Croswel Aguilar;Rafael García;G. Soto-Garrido;R. Arriagada
研究了以活性炭为催化剂的催化湿式空气氧化（CWAO）工艺将氨水氧化为氮气的过程。使用通过用 HNO3 氧化和/或用 H2 还原进行化学改性的商业活性炭 CUDU1000。通过 N2 吸附、热程序分解 (TPD)、傅里叶变换红外 (FTIR) 光谱、Boehm 滴定和零点电荷 (ZPC) 技术对活性炭进行表征。在大气条件下对活性炭上氨水吸附的研究表明，羧基、内酯和酸酐表面基团提高了吸附速率和吸附容量。由于较强的氨吸附作用，氧化碳在 CWAO 工艺中对氨水选择性氧化的活性较低。然而，氢化活性炭对于选择性氨水氧化具有更高的活性。已确定，在羧酸、内酯和/或酸酐表面基团上发生强氨吸附，而醌表面基团负责这些碳所显示的催化活性。
The oxidation of aqueous ammonia to nitrogen by the catalytic wet air oxidation (CWAO) process with activated carbon as catalyst was studied. A commercial activated carbon CUDU1000 chemically modified by oxidation with HNO3and/or reduction with H2was used. The characterization of the activated carbons was carried out by N2adsorption, thermal programmed decomposition (TPD), Fourier transformed infrared (FTIR) spectroscopy, Boehm titration and zero point charge (ZPC) techniques. Studies of aqueous ammonia adsorption on the activated carbons under atmospheric conditions showed that carboxylic, lactonic and anhydride surface groups increase both the rate and capacity of adsorption. The oxidized carbons had lower activity towards selective aqueous ammonia oxidation in CWAO process because of a strong ammonia adsorption. However, hydrogenated activated carbons had higher activity for selective aqueous ammonia oxidation. It is establish that a strong ammonia adsorption takes place onto carboxylic, lactonic and/or anhydride surface groups while the quinonic surface groups are responsible of the catalytic activity shown by these carbons.