低温高效催化湿式氧化处理甲醛废水Pt/MnO_(2)催化剂  

Pt/MnO_(2) catalyst for high-efficiency catalytic wet oxidation of formaldehyde wastewater at low temperature

作　　者：耿莉莉 荣成礼[1] 林艾璇 石海峰 张萌 张诺伟 陈秉辉[1] Lili Geng;Chengli Rong;Aixuan Lin;Haifeng Shi;Meng Zhang;Nuowei Zhang;Binghui Chen(National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China;Department of Chemistry and Applied Chemistry,Changji University,Changji 831100,China)

机构地区：[1]厦门大学化学化工学院,醇醚酯化工清洁生产国家工程实验室,厦门361005 [2]昌吉学院化学与应用化学系,吉昌831100

出　　处：《科学通报》2021年第22期2898-2907,共10页Chinese Science Bulletin

基　　金：国家自然科学基金(21673187);厦门大学校长基金(20720180021)资助。

摘　　要：研究了MnO_(2)形貌对Pt/MnO_(2)催化剂催化湿式氧化(catalytic wet air oxidation,CWAO)处理甲醛废水性能的影响.结果表明,Pt/C-MnO_(2)(蚕茧状MnO_(2)负载Pt)催化剂具有优异的CWAO处理甲醛废水的催化性能.即使在50°C,Pt/C-MnO_(2)的甲醛矿化率高达88.1%,连续反应4次后,甲醛矿化率稳定在80%以上.Pt/R-MnO_(2)(棒状MnO_(2)负载Pt)和Pt/S-MnO_(2)(片状MnO_(2)负载Pt)催化剂活性较低,且随着反应的进行而逐渐失活,连续使用4次后,甲醛矿化率分别由初始的82.2%和82.4%降低至最终的16.3%和35.6%.分散度测定结果表明,Pt/C-MnO_(2)催化剂的Pt具有更好的分散性.X射线光电子能谱和氧气程序升温脱附结果表明,Pt/C-MnO_(2)催化剂具有更丰富的表面氧物种.氢气程序升温还原结果表明,Pt/C-MnO_(2)催化剂具有更低的还原温度和更强的氧化能力.电感耦合等离子体发射光谱结果表明,Pt/C-MnO_(2)催化剂具有更好的抗流失性能.高的分散度、丰富的表面氧物种、强的氧化能力和良好的抗流失性能是Pt/C-MnO_(2)催化剂具有优良催化性能的主要原因.Formaldehyde wastewater,which is mainly from plastics,paper,resin and other industries,not only causes serious environmental problems,but also gives harmful effects to human health.With the increasing environmental concerns,the abatement of formaldehyde wastewater has become an urgent problem.Compared with the conventional technologies,such as the biological treatment,catalytic wet air oxidation(CWAO)has been shown to be an effective and environmentally-friendly way to remove the formaldehyde in water.CWAO technology uses air or oxygen as the oxidant,where the organic can be directly oxidized into CO_(2) and H_(2)O or partially converted to the less toxic compounds by suitable catalysts at elevated temperature and pressure.The key issue of CWAO is to develop a promising catalyst that can work efficiently at low temperature.MnO_(2) is widely applied in the complete oxidation reactions due to its variable valence and abundant crystal structures,but is rarely used in the treatment of formaldehyde wastewater.In this article,Pt/R-MnO_(2)(Pt supported on rod-like-MnO_(2))with very low precious metal content(Pt,0.1 wt%)was prepared by impregnation method.For comparison,Pt/TiO_(2) and Pt/CeO_(2) catalysts were also prepared.The three catalysts with different supports were investigated in the CWAO of formaldehyde wastewater.Pt/TiO_(2) showed the lowest activity and the TOC conversion is less than 35%even at the temperature of 100°C.Pt/CeO_(2) exhibited better catalyst performance.As the reaction temperature increased from 30 to 100°C,the TOC conversion rose from 19.1%to 83.0%.Pt/R-MnO_(2) displayed the most excellent catalytic performance compared with Pt/TiO_(2) and Pt/CeO_(2).At the reaction temperatures of 50 and 80°C,the TOC conversions of Pt/R-MnO_(2) are 82.2%and 89.0%,respectively.MnO_(2) possesses abundant morphologies,which may affect its catalytic performance.The effect of MnO_(2) morphologies on the catalytic performance of Pt/MnO_(2) in formaldehyde wastewater was investigated and the cocoon-like-and sheet-

关 键 词：催化湿式氧化 甲醛废水 Pt/MnO_(2)催化剂 形貌 

分 类 号：X703[环境科学与工程—环境工程] TQ426[化学工程]