稀硝酸催化还原工艺中Pd/AC制备条件优化  

Optimization of Pd/AC preparation conditions for catalytic reduction of dilute nitric acid

作　　者：郑敏 徐垒 陈晨 徐忠宁[4] 付明来[1,3] ZHENG Min;XU Lei;CHEN Chen;XU Zhongning;FU Minglai(Key Laboratory of Urban Pollutant Conversion,Institute of Urban Environment(IUE),Chinese Academy of Sciences,Xiamen 361021,Fujian,China;School of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;Xiamen Key Laboratory of Municipal and Industrial Solid Waste Resource Recovery and Pollution Control,School of Civil Engineering,Huaqiao University,Xiamen 361021,Fujian,China;State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure and Matter,University of Chinese Academy of Sciences,Fuzhou 350002,Fujian,China)

机构地区：[1]中国科学院城市环境研究所城市污染转化重点实验室,福建厦门361021 [2]中国科学院大学资源与环境学院,北京100049 [3]华侨大学土木工程学院厦门市市政与工业固废资源化及污染控制重点实验室,福建厦门361021 [4]中国科学院福建物质结构研究所结构化学国家重点实验室,福建福州350002

出　　处：《化工进展》2022年第7期3938-3946,共9页Chemical Industry and Engineering Progress

基　　金：福建物质结构研究所&城市环境研究所联合研究基金(RHZX-2019-007)。

摘　　要：化工行业中含氮化合物的超标排放是水中氮元素的来源之一,硝酸是化工行业的重要原料。煤制乙二醇过程会产生大量的稀硝酸副产物,通过硝酸催化还原反应,可以将其进一步转化为亚硝酸甲酯,从而实现资源回收利用,同时减少水中氮源的输入,有利于控制水体富营养化的发生。活性炭负载钯(Pd/AC)材料作为催化剂能有效提升硝酸转化率。本研究通过等量浸渍法制备Pd/AC,结合高分辨率透射电子显微镜(HRTEM)、X射线衍射(XRD)、物理吸附仪和X射线光电子能谱(XPS)表征结果,分别考察了不同的煅烧和还原条件对材料的结构以及硝酸催化还原活性的影响,优化Pd/AC的制备条件。结果表明,煅烧温度的升高、煅烧时间和还原时间的延长会造成Pd颗粒粒径增加;单质钯与氧化态钯的比值(Pd∶PdO)增加,会造成比表面积和孔容减小,从而导致Pd/AC的催化活性降低。One of the nitrogen sources in water is the excessive discharge of nitrogen-containing compounds by chemical industry,such as nitric acid.A large amount of nitric acids produced in the process of coal to ethylene glycol as by-product could be further converted to methyl nitric through catalytic reduction.This strategy could realize resource recycling,reduce nitrogen input in water,and control the occurrence of entrophication in water bodies.Activated carbon supported Palladium(Pd/AC)catalyst can effectively increase the conversion of nitric acid.In this study,Pd/AC was prepared by impregnation method,and characterized by high resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD),physical adsorption,and X-ray photoelectron spectroscopy(XPS).The effects of calcination and reduction condition on the structure of material and catalytic reduction activity of nitric acid were investigated to optimize the preparation conditions.The results indicated that with the increase of the calcination temperature,and the extension of the calcination time and the reduction time,the Pd particle size and the ratio of elemental palladium to oxidized palladium(Pd∶PdO)were increased,while the specific surface area and pore volume both decreased,which would lower the catalytic activity.

关 键 词：硝酸 催化还原 活性炭负载钯 转化率 优化 

分 类 号：TQ111.26[化学工程—无机化工]