Controllable Synthesis Of Ru-based Composite Nanomaterials And Research On Electrolysis Of Water For Hydrogen Production

Hydrogen production by electrolysis of water as a green and efficient hydrogen production method has been widely concerned.The precious metal Ru has a good application prospect in the field of energy conversion due to its high activity and much lower price than commercial Pt catalyst.However,how to further improve the atomic utilization and stability of Ru is the core scientific problem in the design and preparation of this type of catalyst.In this paper,the surface defect sites of transition metal compounds（TM（S,O）_S）were accurately controlled by solid-liquid and solid-solid combined methods,and Ru was modified by vacancy defect effect to obtain TM（S,O）_S cured cluster catalyst（Ru-TM（S,O）_S）.The hydrogen evolution（HER）electrocatalytic reactivity of Ru-TM（S,O）_Swas further investigated.Finally,the electronic structure,adsorption energy and Gibbs free energy of Ru-TM（S,O）_S were calculated by density functional theory（DFT）,and the electrochemical reaction mechanism and catalysis mechanism of Ru-TM（S,O）_S were investigated.（1）RuRh bimetallic nanorings with abundant structural defects were successfully synthesized by one-step solvothermal method at atmospheric pressure.The electrochemical hydrogen evolution performance of RuRh bimetallic nanorings was tested under different p H conditions.The results show that the performance of both RuRh bimetallic nanorings is better than that of commercial Pt catalysts and mono-metal catalysts,especially in acidic medium.After 30000 cyclic voltammetry tests,stable hydrogen release can also be maintained.A combination of atomic-scale structure observation and density functional theory calculations demonstrates that both the grain boundaries and symmetry breaking of RuRh₂ bimetallene cannot only weaken the adsorption strength of atomic hydrogen,but also facilitate the transfer of electrons and the adsorption of reactants,further boosting the HER electrocatalytic performance in all p H values.（2）By using a facile solid-liquid phase chemical strategy for in situ formation of cation vacancies in a five-fold twinned Pt Pd Ru Te anisotropic structure(v-Pd₃Pt₂₉Ru₆₂Te₆ AS).Due to the synergy of metal vacancies and twinned structural advantages,including proper hydrogen bonding energy,large surface exposure area,anisotropic structure and fast mass/charge transport,v-Pd₃Pt₂₉Ru₆₂Te₆AS exhibits excellent HER electrocatalytic performance,in alkaline and acidic electrolytes,the overpotential is as low as 22 m V and 39 m V at j=10 m A cm^-2,and the stability can reach 30 h.（3）A strategy to grow multiheterogeneous cobalt phosphide（Co P）nanorods with rich interfaces and defects along the one-dimensional（1D）nanostructure by dual incorporation of Fe and Ru（Co Fe P@Ru）.Such a catalyst shows superior activity and stability towards the hydrogen evolution reaction（HER）and oxygen evolution reaction（OER）,with overpotentials of only 38 m V in 0.5 M H₂SO₄ and 48 m V in 1.0M KOH for HER,and an overpotential of 340 m V in 0.1 M KOH for OER at 10 m A cm^-2.In addition,as the bifunctional catalyst,an alkali electrolyzer is assembled and delivers at a low cell voltage,with almost 100%Faradaic efficiency.