PtRu/氮掺杂碳电催化甲醇氧化及电解水析氢性能

PtRu/nitrogen-doped carbon for electrocatalytic methanol oxidation and hydrogen evolution by water electrolysis

将三聚氰胺、RuCl_(3)及炭黑以一定的比例分散于乙醇中,采用旋转蒸干及高温热处理合成了一种氮掺杂碳(NC)负载Ru的Ru/NC催化剂。采用硼氢化钠液相化学还原法合成了不同Pt、Ru负载量的PtRu/NC催化剂,并用于电催化甲醇氧化反应(MOR)及电催化分解水析氢反应(HER)。结果表明,合成的催化剂中Pt_(1)Ru/NC(Pt、Ru的实际负载量分别为1.14%、0.54%)表现出最优的MOR性能,质量活性达4.96 A·mg^(-1)_(PtRu),且经10000 s稳定性测试后质量活性保持在测试前的91.1%。同时,当电流密度为100mA·cm^(-2)时,Pt_(1)Ru/NC在HER中表现出最低的过电位(103 mV)和最小的Tafel斜率(15.29 mV·dec^(-1))。通过X射线衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、扫描透射电子显微镜(STEM)、电感耦合等离子体发射光谱(ICP-OES)、STEM-能谱(STEM-EDS)技术表征了PtRu/NC双金属催化剂,其具有优异催化性能的原因如下:(1)PtRu双金属纳米颗粒高度分散于NC上;(2)Pt以纳米团簇或单原子形式负载于Ru上,后负载于NC,形成了Pt-Ru相分离结构;(3)Pt、Ru与N之间存在协同效应。

Melamine,RuCl_(3),and carbon black were dispersed in ethanol with a certain proportion,and a nitrogendoped carbon(NC)-supported Ru catalyst(Ru/NC)was synthesized by spin evaporation drying and high-temperature thermal treatment.The PtRu/NC catalysts with different Pt and Ru contents were synthesized by sodium borohydride liquid phase chemical reduction,which was used for electrocatalytic methanol oxidation reaction(MOR)and hydrogen evolution reaction(HER)by water electrolysis.The results showed that Pt_1Ru/NC(mass fraction:1.14%for Pt,0.54%for Ru)had the best MOR performance among as-synthesized catalysts,with a mass activity of 4.96 A·mg^(-1)_(PtRu),and it maintained 91.1%of the initial mass activity after 10000 s stability test.In addition,when the current density was 100 mA·cm^(-2),Pt_1Ru/NC exhibited the lowest overpotential(103 mV)and the sruallest Tafel slope(15.29 mV·dec^(-1))for HER.The characterization techniques of X-ray diffractometer(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),scanning transmission electron microscopy(STEM),inductively coupled plasma-optical emission spectroscopy(ICP-OES),and STEM-energy-dispersive X-ray spectroscopy(STEM-EDS)were used to analyze the reasons for excellent catalytic performance of Pt_1Ru/NC,as follows:firstly,the PtRu bimetallic nanoparticles are highly dispersed on NC;secondly,Pt is loaded on Ru with nanoclusters or single atoms,forming Pt-Ru phase segregation;thirdly,there is a synergistic effect between Pt,Ru,and N.