论文部分内容阅读
近年来,环境污染特别是水的严重污染使其治理成为一个极具挑战性的课题.各种污染物复杂的化学成分和催化剂在处理过程中的浸出、寿命及成本等问题是导致众多氧化催化剂难以实际应用的主要原因.相对而言,H_2O_2是一种活性氧含量高、清洁并可在温和条件下使用的氧化剂,在各种高级氧化技术中受到广泛关注.而碳酸氢盐是一种弱碱性物质,在自然界及水体系中广泛存在,且无明显毒害.它可活化H_2O_2,加快其氧化各种有机物,并在废水处理领域开始受到关注.该体系的明显优势在于处理体系始终处于微碱性环境,可以有效避免金属氧化物催化剂在处理过程中由于体系酸化而带来的催化剂流失,从而延长催化剂寿命,降低催化剂成本.本文采用浸渍法制备了一种双金属铜、钴氧化物催化剂及相关的对照催化剂体系,利用碳酸氢盐活化H2O2用于降解苯酚模拟废水.通过各种空白实验发现,负载于γ-Al_2O_3表面的钴、铜氧化物催化剂CuO-Co_3O_4@γ-Al_2O_3具有最好的催化降解活性,而CuO@γ-Al_2O_3,Co_3O_4@γ-Al_2O_3,Cu O-Co_3O_4及CuO和Co_3O_4的物理混合物均表现出较差的催化性能.由此可见,在CuO-Co_3O_4@γ-Al_2O_3催化剂中,铜、钴离子在苯酚降解过程中存在协同效应,这可能与催化剂中钴、铜金属离子的相互作用相关.X射线衍射和X射线光电子能谱结果表明,反应前后CuO-Co_3O_4@γ-Al_2O_3催化剂中金属的氧化状态并未发生改变,在使用过程中钴离子的浸出率可以忽略,铜离子的浸岀率也仅有0.6 ppm.荧光分析实验和自由基捕获实验表明,只有添加·O_2~-和·OH的捕获剂能明显抑制降解反应,因而推测该反应体系对有机物的降解是一个自由基氧化过程,起关键作用的可能是·O_2~-和·OH.
In recent years, the serious pollution caused by environmental pollution, especially water makes it a challenging task.The complex chemical composition of various pollutants and catalyst leaching in the treatment process, life expectancy and cost and other issues lead to many oxidation catalysts H 2 O 2 is a kind of oxidant with high active oxygen content, which is clean and can be used under mild conditions, and is widely concerned in various advanced oxidation technologies. However, bicarbonate is a kind of weak Alkaline substances exist widely in nature and in water system, and are not obviously poisonous.It can activate H 2 O 2 and accelerate its oxidation of various organic compounds, and begin to be noticed in the field of wastewater treatment.The obvious advantage of this system is that the treatment system is always in the micro Alkaline environment can effectively prevent catalyst loss due to acidification of the metal oxide catalyst during treatment, thereby prolonging the life of the catalyst and reducing the cost of the catalyst.In this paper, a bimetallic copper and cobalt oxide catalyst And related control catalyst systems, the use of bicarbonate activated H2O2 for the degradation of phenol simulated wastewater by Various blank experiments showed that CuO-Co_3O_4 @ γ-Al_2O_3 supported on the surface of γ-Al_2O_3 has the best catalytic activity, and CuO @ γ-Al_2O_3, Co_3O_4 @ γ-Al_2O_3, Co_3O_4 and the physical mixtures of CuO and Co_3O_4 all showed poor catalytic performance.Therefore, in the CuO-Co_3O_4 @ γ-Al_2O_3 catalyst, there is a synergistic effect of copper and cobalt ions in the phenol degradation process, which may be related to the catalyst Cobalt and copper ions.The results of X-ray diffraction and X-ray photoelectron spectroscopy show that the oxidation states of CuO-Co_3O_4 @ γ-Al_2O_3 catalysts did not change before and after the reaction, and the leaching of cobalt ions The rate of negligible copper ion leaching rate was only 0.6 ppm.Fluorescence analysis experiments and free radical trapping experiments showed that only the addition of · O 2 - and · OH capture agent can significantly inhibit the degradation reaction, suggesting that the reaction system The degradation of organic matter is a free radical oxidation process, which may play a key role as O 2 ~ - and · OH.