低品位褐铁矿尾矿复合催化剂室温下净化甲醛  

Low Grade Limonite Tailings Combined Catalyst for Formaldehyde Purification at Room Temperature

作　　者：周之琳 陈天虎[1] 王灿[1] 韩正严 邹雪华[1] 刘海波[1] ZHOU Zhilin;CHEN Tianhu;WANG Can;HAN Zhengyan;ZOU Xuehua;LIU Haibo(Key Laboratory of Nano-Minerals and Pollution Control of Anhui Higher Education Institutes,School of Resources&Environmental Engineering,Hefei University of Technology,Hefei 230009 China)

机构地区：[1]合肥工业大学资源与环境工程学院,纳米矿物与污染控制安徽省普通高校重点实验室,合肥230009

出　　处：《硅酸盐学报》2023年第10期2680-2688,共9页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(42102029)。

摘　　要：对铜陵叶山铁矿开采所产生的低品位褐铁矿尾矿(LT)进行探究,旨在发掘其在室温净化甲醛领域中的应用价值及其载体性能。通过分析该尾矿的成分,发现其含有纳米针铁矿、石英等矿物,具有较大的比表面积,适合作为催化剂载体。采用化学还原法将δ-MnO_(2)(Bir)负载于尾矿颗粒表面,制备了一系列不同锰含量的除醛催化剂(x-Bir/LT)。结果表明:该催化剂具有良好的催化降解甲醛的能力。在甲醛初始浓度为1.2 mg/m^(3),体积空速为260000 h^(-1)的条件下,27.3-Bir/LT在600 min时净醛效果仍有97.2%,并且具有长时间稳定性和抗水性。通过原位红外光谱分析发现,甲醛在催化剂表面反应的机制为:甲醛被表面羟基吸附后氧化成H^(+)和HCOO^(-),并经过羟基和表面活性氧氧化,进一步分解成CO_(2)和H_(2)O。同时,氨气吸附原位红外分析发现,该尾矿能为催化剂提供大量的L-酸位点,提高了复合催化剂的催化氧化能力。因此以褐铁矿尾矿为催化剂的载体可以提升复合催化剂的净醛能力,为其用于室内甲醛等污染治理提供了理论支撑。The application and performance of low-grade limonite tailings(LT)from Yeshan Iron Mine(Tongling,China)were investigated for the formaldehyde purification at ambient temperature.According to the composition analysis of the tailings,the presence of minerals like nanoneedle hematite and quartz with a great specific surface area is suitable as a catalyst carrier.In this paper,birnessite(Bir)was loaded onto the surface of LT particles via chemical reduction to prepare a catalyst for formaldehyde removal with different manganese loads(x-Bir/LT).The results show that the catalyst has a good formaldehyde degradation ability.The removal efficiency of 27.3-Bir/LT is still 97.2% after 600 min at an initial formaldehyde concentration of 1.2 mg/m^(3) and a gas hourly space velocity of 41.6 m^(3)/s,thus having a long-term stability and a water resistance.According to the analysis by in-situ infrared spectroscopy,formaldehyde reacts on the catalyst surface via being adsorbed by surface hydroxyl groups and then oxidized to H^(+)and HCOO^(-),which further decomposes into CO_(2) and H_(2)O through hydroxyl and surface reactive oxygen species oxidation.Also,LT provides a large number of L-acid sites for the catalyst,improving the catalytic oxidation performance of the composite catalyst.Using limonite tailings as a catalyst carrier can enhance the catalytic oxidation performance of the composite catalyst.This work provides a technical reference for its application in indoor formaldehyde pollution control.

关 键 词：褐铁矿尾矿 甲醛 催化氧化 环境温度 L-酸位点 

分 类 号：TB33[一般工业技术—材料科学与工程]