Preparation Of Ruthenium Composites And Their Electrocatalytic Hydrogen Evolution Properties

As a new type of green energy,hydrogen（H₂）has the attributes of high energy density,durability,and environmental friendliness.Therefore,the development of hydrogen energy has important strategic significance for the optimization of China’s energy structure and the implementation of the"dual carbon"policy.Hydrogen production by water electrolysis is the most ideal method for hydrogen production,but the lack of cheap and high-quality catalysts limits the application of water electrolysis on a larger scale.At present,platinum carbon catalyst is the most effective HER catalyst for water electrolysis,but its high price restricts its large-scale commercialization.Ruthenium in platinum series metals has the characteristics of relatively low price,strong corrosion resistance,strong metal hydrogen bond strength(65kcal mol^-1),and more and more researchers have designed and applied it.Among them,the support of HER catalyst supported matrix can not only reduce the cost of the catalyst,but also carry and regulate the active sites of metals.Therefore,carbon black（CB）-titanium dioxide（Ti O₂）support and nitrogen doped layered porous carbon support were designed in this thesis,and simple ruthenium based composite materials are prepared.The main work is as follows:（1）In this experiment,CB-Ti O₂precursor was prepared by hydrothermal and sintering methods with carbon black,Ti O₂as raw materials,and then Ru-CB/Ti O₂composites were prepared by solvothermal reaction with Ru Cl₃·3H₂O,and then sintered at high temperature.The effect of Ru Cl₃·3H₂O addition on the sample preparation was investigated.The experimental results showed that the Ru-CB/Ti O₂composites were successfully prepared,and the Ru-CB/Ti O₂4:1 composites had the best HER performance.In 1M KOH alkaline medium,the overpotential was 53 m V at10 m A cm^-2current density,and the Tafel slope was 88 m V dec^-1;In 0.5M H₂SO₄acid medium,the overpotential at 10 m A cm^-2current density is 116m V,and the Tafel slope is 86m V dec^-1.（2）In this experiment,nitrogen doped hierarchical porous carbon（NHPC）with three-dimensional structure was prepared from soluble starch,ammonium citrate and sodium bicarbonate by high-temperature carbonization,and then mixed with Ru Cl₃·3H₂O under ultrasonic environment to prepare Ru/NHPC composites by Na BH₄reduction.The effect of Ru Cl₃·3H₂O addition on the sample preparation was investigated.The results show that NHPC with ultra-high specific surface area and N doping is more conducive to the improvement of HER performance;Ru/NHPC-0.05has the best performance of HER.In 1M KOH alkaline medium,the overpotential is33 m V at 10 m A cm^-2current density,and the Tafel slope is 36 m V dec^-1;In 0.5M H₂SO₄acid medium,the overpotential at 10m A cm^-2current density is 76m V,and the Tafel slope is 48m V dec^-1.