水电解电催化材料合成、微结构调控及性能研究

发布时间：2018-05-21 06:07

  本文选题：质子交换膜水电解 + 析氧反应　； 参考：《北京科技大学》2016年博士论文

【摘要】：质子交换膜(PEM)水电解制氢技术具有效率高、气体纯度高、安全可靠和寿命长等优点,可与太阳能、风能发电等联用作为储能和能量转化装置,被视为未来能源和环境协调发展的重要选择。然而,电解制氢过程电催化材料可逆性差、反应动力学过程缓慢以及微结构、多相界面等因素不足制约了PEM水电解制氢的工业化进程。为了降低电极反应损失,有必要研制高活性、低成本的电催化材料。本论文以提高析氧与析氢电催化活性,提高催化层内电催化材料利用率为目标,从组分与微结构出发,依据电催化反应进程,优化电催化材料和催化层内部的电子、质子和气液传输过程。主要开展了以下三个方面的研究工作：一、采用复合载体思路,探索载体材料组分与微结构的可控制备方法,考察载体材料与活性组分交互支持作用对电催化活性的影响机理。从材料组分的角度,通过原位掺杂方法制备磷钨酸铯与锑掺杂的二氧化锡不同比例的复合载体材料,该复合载体材料不仅具有较高的电子传导能力和纳米球状结构,更重要的是自身具有质子传导性特性,有助于活性组分良好分散、新活性位点建立和催化层内部质子导电性的提高。从微结构的角度,采用静电纺丝的方法和后续煅烧过程制备了锑掺杂二氧化锡多孔结构的纳米纤维,相比纳米颗粒结构,活性组分得到更好地分散,同时促进活性组分表面荷电传输和气、液传输过程。单池性能测试表明,相比纯的二氧化铱催化剂,复合载体材料负载型电催化剂显示出较好的析氧活性。80℃,2 A cm-2下,槽压分别下降了60 mV和100 mV(催化剂载量：1.5 mg cm-2)。二、为降低欧姆损失和动力学极化损失,在Nafion骨架中引入高质子电导率的磷钨酸铯,提升质子导电相的电导率。进一步优化了催化层中质子导电聚合物的添加量。催化层中电催化材料与质子导电聚合物质量比例为9：1时,获得了最佳的单池性能,80℃,2 Acm-2下,槽压仅有1.59 V(催化剂载量：1.5 mg cm-2)。三、从以下两个方面开展非贵金属析氢电催化材料研究：首先,制备高分散的非晶态镍磷粉体材料,并结合煅烧处理工艺,制得晶态镍磷材料,研究晶相组成、晶体结构及晶粒尺寸对析氢活性的影响。所制备的非晶态Ni-P具有良好的析氢活性,电流密度20 mA cm-2下过电位为262 mV vs NHE。经300℃煅烧处理后所得的混晶结构镍磷粉体,析氢活性得到进一步提升,电流密度20 mA cm-2下过电位为154 mV vs NHE(镍磷催化剂载量为2 mg cm-2)。进一步采用化学镀的方法以不锈钢毡为基体负载非晶态镍磷合金。将其用于析氢电极,电流密度20 mA cm-2时,过电位为224 mV vs HE。组装单池后,80℃,电流密度为500 mA cm-2对,槽压为2.06 V(阳极催化剂载量：1.5 mg cm-2,阴极镍磷合金载量为10 mg cm-2)。
[Abstract]:Proton exchange membrane PEM) water electrolytic hydrogen production technology has the advantages of high efficiency, high gas purity, safety, reliability and long life. It can be used as energy storage and energy conversion device in conjunction with solar and wind power generation. Is regarded as the future energy and environment coordinated development important choice. However, the low reversibility of electrocatalytic materials, the slow reaction kinetics and the insufficiency of microstructure and multi-phase interface in the process of electrolysis hydrogen production have restricted the industrialization process of hydrogen production by PEM water electrolysis. In order to reduce the loss of electrode reaction, it is necessary to develop electrocatalytic materials with high activity and low cost. The aim of this thesis is to improve the electrocatalytic activity of oxygen evolution and hydrogen evolution, and to improve the utilization ratio of electrocatalytic materials in the catalytic layer. According to the process of electrocatalytic reaction, the electrocatalytic materials and the internal electrons in the catalytic layer are optimized according to the composition and microstructure. Proton and gas-liquid transport process. The main research work is as follows: 1. By using the idea of composite carrier, the controllable preparation method of the component and microstructure of the carrier material is explored, and the mechanism of the interaction support between the carrier material and the active component on the electrocatalytic activity is investigated. From the point of view of material composition, the composite carrier material with different proportion of cesium phosphotungstate and antimony doped tin dioxide was prepared by in-situ doping method. The composite carrier material not only has high electron conductivity and nanometer spherical structure. More importantly, it has proton conductivity, which is helpful to the good dispersion of active components, the establishment of new active sites and the improvement of proton conductivity in the catalytic layer. From the point of view of microstructure, antimony doped tin dioxide nanofibers with porous structure were prepared by electrospinning and subsequent calcination process. At the same time, the surface charge transport and gas and liquid transport of active components are promoted. The single cell performance test showed that compared with the pure iridium oxide catalyst, the composite supported electrocatalyst showed better oxygen evolution activity at 80 鈩，

本文编号：1918054