文献类型：期刊文献

中文题名：沉积沉淀法制备氧化钼纳米带负载的钼酸铁催化剂

英文题名：The MoO3 Nano-Belt Supported Iron Molybdate Catalyst Prepared by Deposition-Precipitation Method

作者：汪超[1];张衡[2];李平[2];金国杰[1]

机构：[1]中国石油化工股份有限公司上海石油化工研究院绿色化工与工业催化国家重点实验室,上海201208;[2]华东理工大学化学工程联合国家重点实验室,上海200237

年份：2019

卷号：35

期号：4

起止页码：296

中文期刊名：化学反应工程与工艺

外文期刊名：Chemical Reaction Engineering and Technology

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；

语种：中文

中文关键词：钼酸铁;三氧化钼;沉积沉淀法;甲醛

外文关键词：iron molybdate;molybdenum oxide;deposition-precipitation method;formaldehyde

摘要：在Fe2(MoO4)3/MoO3异质负载结构的基础上,为进一步调变负载Fe2(MoO4)3的尺寸,强化Fe2(MoO4)3与MoO3的接触,采用沉积沉淀法在MoO3纳米带上载铁,并进一步焙烧形成钼酸铁催化剂.通过ICP原子发射光谱(ICP-AES)、X射线衍射(XRD)、傅立叶红外光谱(FT-IR)、N2物理吸附和扫描电子显微镜(SEM)等手段表征了催化剂的组成、结构和形貌特征,评价了催化剂在甲醇氧化制甲醛反应中的性能.结果表明:沉积沉淀法制备的催化剂以Fe2(MoO4)3和MoO3为主要成分,且Fe2(MoO4)3微粒呈群岛状密布于MoO3纳米带表面,不同于浸渍方法形成的聚团状Fe2(MoO4)3.沉积沉淀法催化剂在反应中表现出显著的高活性和较好的甲醛选择性.进一步研究表明沉淀过程的终点pH值对催化剂的组成和形貌有显著影响.提高终点pH值可以增加催化剂中的Fe2(MoO4)3,提高催化剂活性,但可能导致副产一氧化碳增加,最优的选择性对应沉淀终点pH值在2.5~3.0.以此得出结论:减小Fe2(MoO4)3微粒的尺寸并且令其与MoO3紧密接触的结构特征有利于改善铁钼催化剂的性能.
In order to adjust the size of Fe2(MoO4)3 particles supported on the MoO3 and to enhance the intimate contact between them,ferrous composition was precipitated and deposited on the MoO3 nano-belt which was synthesized in the hydrothermal system,and then calcined to ferric molydbate.The prepared catalysts were characterized by inductive coupled plasma-atomic emission spectrometry(ICP-AES),X-ray diffraction(XRD),fourier transform infrared spectroscopy(FT-IR),N2 physical adsorption and scanning electron microscope(SEM),and were evaluated for the selective oxidation of methanol to formaldehyde.It was showed that the catalyst prepared by deposition-precipitation method(DP)consisted of Fe2(MoO4)3 and MoO3,the islands of fine particles which is Fe2(MoO4)3 were densely distributed on the surface of the MoO3 nano-belt,different from the impregnation method(IM)which will lead to the agglomerate Fe2(MoO4)3.The DP catalyst gave the significantly superior activity and the better selectivity.Moreover,the pH value to the end of the precipitation affected the catalyst remarkably,with higher pH value,the Fe2(MoO4)3 increased and offered more reactivity,yet the by-product of CO may also be promoted.The modest pH value was 2.5-3.0,which optimized the selectivity to formaldehyde.As a conclusion,it will be beneficial to the Mo-Fe catalyst to reduce the size of Fe2(MoO4)3 and meanwhile intimately adhere them to MoO3.