碳负载钯或钯基纳米复合物的制备及电催化性能研究

发布时间：2018-02-27 15:36

本文关键词： 钯纳米粒子钯镍合金铂钯合金抗坏血酸多巴胺尿酸过氧化氢电催化　出处：《吉林建筑大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着纳米技术的迅速发展,贵金属纳米粒子因其具有大的比表面积,表面原子数目众多以及表面原子的价键不饱和,在电化学催化等领域展现了极大的应用价值。就贵金属Pt纳米粒子作催化剂的研究现状而言,昂贵的价格和高载用量以及极化电位过高等缺点都极大地限制了其商业化开发。负载型Pd基纳米催化剂具有良好的催化性能,且相对于Pt具有更低的成本,故本文通过调控载体的类型、催化剂成分、钯的形貌、尺寸和含量等因素控制催化剂的催化活性,并研究了其电催化性能,具体内容如下:1利用简单的乙二醇还原法在成功地制备了活性炭负载不同Pd含量(20%、30%和40%)的C/Pd纳米催化剂。采用XRD、XPS和TEM对其组成结构与形貌进行了表征。结果表明,Pd纳米粒子成功的负载在XC-72炭载体上,且颗粒分散度窄,分布均匀,无聚集现象。采用循环伏安法(Cyclic voltammetry,CV)、差分脉冲伏安法(Differential pulse voltammetry,DPV)在中性条件下表征所制备的样品对抗坏血酸(ascorbic acid,AA)、多巴胺(Dopamine,DA)和尿酸(Uric acid,UA)的电催化性能,结果表明,当Pd含量在30%时催化剂具有最好的活性。CV曲线显示AA、DA和UA的氧化峰位差分别为219 m V(DA-AA)、106m V(UA-DA)和325m V(UA-AA),说明可以同时检测AA、DA和UA。在差分脉冲伏安法的检测中,DA-AA、UA-DA和UA-AA的峰位差分别达到了215m V、129 m V和344 m V,这就使得C/Pd催化剂成为同时检测AA、DA和UA的良好选择。2采用两步实验法制备了活性炭负载钯/磷化镍(C/Ni_2P/Pd)纳米复合材料,研究了所制备样品修饰的玻碳电极对过氧化氢的电催化性能。利用XRD、XPS、TEM和EDX对其组成结构、形貌和元素分布情况进行了表征。结果表明,Pd、Ni_2P纳米粒子成功地负载在XC-72炭载体上,颗粒分散均匀,粒径约为2~5 nm。C/Ni_2P/Pd修饰的电极对过氧化氢(H_2O_2)展现出优良的电催化活性,工作电压低至-0.5 V,具有快速的安培响应时间(3 s),较高的灵敏度,较宽的线性范围(0.25~35 m M),检测限为0.05 m M。另外,C/Ni_2P/Pd纳米材料修饰电极还展现出了良好的重现性、稳定性和抗干扰性。3通过一步法制备了三维石墨烯(3D GE)修饰的双金属Pt Pd纳米粒子复合材料,并用于作为H_2O_2的电化学检测。采用SEM和拉曼光谱的等技术对3D GE/Pt Pd复合物的形貌和结构进行了分析,结果表明3D GE/Pt Pd复合物由石墨烯片相互搭接组装成三维孔状结构,Pt Pd纳米粒子均匀地分布在3D GE表面。我们利用CV、计时电流行为研究了3D GE/Pt Pd复合物对H_2O_2的电催化性能,并实现了低浓度检测,线性检测范围达到0.25~2.0 m M(R=0.993),灵敏度为219.6μA m M~(-1) cm~(-1)。
[Abstract]:With the rapid development of nanotechnology, noble metal nanoparticles have a large specific surface area, a large number of surface atoms and unsaturated valence bonds of surface atoms. It has shown great application value in the field of electrochemical catalysis and so on. The high price, high loading amount and high polarization potential greatly limit the commercial development of the catalyst. The supported PD based nanocatalysts have good catalytic performance and lower cost compared with Pt. Therefore, the catalytic activity of the catalyst was controlled by controlling the type of the carrier, the composition of the catalyst, the morphology, size and content of palladium, and the electrocatalytic activity of the catalyst was studied. The main contents are as follows: 1. C / PD nanocatalysts with different PD contents (30% and 40%) were successfully prepared by using simple ethylene glycol reduction method. The structure and morphology of the catalysts were characterized by XRDX XPS and TEM. Pd nanoparticles were successfully loaded on XC-72 carbon support. Under neutral conditions, the electrocatalytic properties of the prepared samples for ascorbic acid, dopamine dopamineDAA) and uric acid UCA were characterized by cyclic voltammetry and differential pulse voltammetry. The results show that. When PD content is 30%, the catalyst has the best activity. CV curve shows that the oxidation peak difference of AADA and UA are 219mVtDA-AAO106m VUA-DAA) and 325mVTU UA-AADAA, respectively, indicating that both ADA and UAare can be detected simultaneously. In differential pulse voltammetry, the peak position of DA-AU UA-DA and UA-AA can be detected. The difference reached 215 MV 129mV and 344 MV respectively, which made the C / PD catalyst a good choice for the simultaneous detection of AA DA and UA. 2. The activated carbon supported PD / Ni / Ni 2P / PD nanocomposites were prepared by two step experiments. The electrocatalytic properties of the modified glassy carbon electrode for hydrogen peroxide were studied. The structure, morphology and element distribution of the modified glassy carbon electrode were characterized by TEM and EDX. The results showed that the PdTiNi2P nanoparticles were successfully supported on the XC-72 carbon carrier. The electrode with a particle size of about 2 ~ 5 nm.C/Ni_2P/Pd showed excellent electrocatalytic activity for H _ 2O _ 2 H _ 2O _ 2. The working voltage was as low as -0.5 V, and the electrode had high sensitivity and rapid amperometric response time. The detection limit is 0.05 mm. In addition, the C / Ni _ 2P / PD nanomaterials modified electrode also shows good reproducibility, and the detection limit is 0.05 mm 路m ~ (-1), and the linear range is 0.25 渭 m 路m ~ (-1), and the detection limit is 0.05 mm 路m ~ (-1). The bimetallic Pt PD nanocomposites modified by three-dimensional graphene and 3D GE were prepared by one-step method with stability and anti-interference. The structure and morphology of 3D GE/Pt PD complex were analyzed by SEM and Raman spectroscopy. The results show that 3D GE/Pt PD complexes are assembled by overlap of graphene sheets to form 3D pore structure Pt PD nanoparticles uniformly distributed on the surface of 3D GE. The electrocatalytic properties of 3D GE/Pt PD complexes for H _ 2O _ 2 have been studied by means of CVC and chronoamperometric behavior. The low concentration detection was achieved. The linear detection range was 0.25m ~ (2. 0) m ~ (-1) and the sensitivity was 219.6 渭 A / m ~ (-1) 路cm ~ (-1) 路m ~ (-1) 路m ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1).
【学位授予单位】：吉林建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

【相似文献】