Ru和Cu协同催化湿式氧化处理氨氮废水

Synergetic effect of Ru and Cu on catalytic wet oxidation of ammonia-wastewater

采用化学还原法制备了RuCu/TiO_2双金属催化剂,并探究了Ru和Cu的协同作用对催化湿式氧化(CWAO)无害化处理氨氮废水催化性能的影响。研究结果表明,Cu的添加可有效改善Ru/TiO_2催化剂的N_2选择性,而Ru的存在可有效提高Cu/TiO_2催化剂的催化活性。反应条件为0.5 MPa、150℃、[NH_3]0=1000 mg·L^(-1)、pH=12、模拟废水处理量为33 L·(kg cat)^(-1)·h^(-1)时,1Ru2Cu/TiO_2能使废水的氨氮转化率和N_2选择性分别高达87.7%和85.9%。表征结果表明:Ru和Cu的协同在催化氧化氨氮废水过程中起了关键作用,主要体现在:Ru和Cu的强相互作用导致1Ru2Cu/TiO_2催化剂具有良好的抗流失性能,进而使得催化剂具有良好的稳定性;Ru和Cu的电子转移使得1Ru2Cu/TiO_2具有适中的亲氧性能,有效提高了催化剂的催化活性。

RuCu/TiO2 bimetallic catalysts which were prepared via chemical reduction methods and the synergetic effect between Ru and Cu in the detoxification of ammonia-wastewater to nitrogen via catalytic wet air oxidation(CWAO)were investigated.The results showed that the addition of Cu in Ru/TiO2 can effectively improve the selectivity of N2,while the presence of Ru in Cu/TiO2 can greatly enhance the catalytic activity of the catalyst.The catalyst(1Ru2Cu/TiO2)with 1%and 2%loading of Ru and Cu has the best catalytic performance among the prepared catalysts.With the reaction conditions of 0.5 MPa,150℃,[NH3]0=1000 mg·L?1,pH=12 and the application to the simulated wastewater was about 33 L·(kg cat)?1·h?1,1Ru2Cu/TiO2 achieved 87.7%ammonia conversion and 85.9%N2 selectivity.The characterization results demonstrated that the synergetic effect of Ru and Cu played a key role in the catalytic of the ammonia to nitrogen,mainly reflects in the following:the strong interaction between Ru and Cu results in good anti-leaching of 1Ru2Cu/TiO2 catalyst,leading to excellent stability for the catalyst.The electron transfer between Ru and Cu makes 1Ru2Cu/TiO2 has a moderate oxygen affinity,which has effectively enhanced the catalytic activity of the catalyst.