Preparation And Catalyticalof N Performance Ni-based Ni/RuO₂Composite Electrodes And Ni-P Alloy Electrodes For Hydrogen Evolution Reaction

Chlor-alkali industry is the basic material industry of our country and also anenergy-intensive industry. The energy consumption of chlorine production accounts forapproximately50%of the manufacturing costs in the energy-intensive chlor-alkaliindustry, which has restricted the development of water electrolysis and chlor-alkaliindustry. With the rapid development of science and technology, it has become animportant research subject how to reduce energy consumption, raise economic benefitsand improve the technology level of chlor-alkali industry. Currently, the over-potentialof dimensionally stable anode （DSA） for chlorine evolution reactioin （CER） is relativelylow （about30mV）, however, the over-potential of the cathode for hydrogen evolutionreaction （HER） reaches up to50-400mV, which is the main factor for increasing cellvoltage in the electrolysis. In addition, hydrogen production by water electrolysis alsoexist the problems of high cell voltage and large energy consumption. Therefore, tofurther reduce energy consumption of chlor-alkali industry and water electrolysis,design and preparation of a novel cathode with high electrocatalytic activity, long-termstability and inexpensive has very important theretical significance and practical value.In present work, Ni-based Ni/RuO₂composite electrode and Ni-P alloy electrode wereprepared by pulse electrodeposition method. The preparation conditions andelectrocatalytic performance of these electrodes were also systematically studied.Ni-based Ni/RuO₂composite electrode was prepared by pulse electrodeposition andthermal decomposition method. The morphology, structure and composition of theas-prepared electrodes were characterized by scanning electron microscopy （SEM）,energy-dispersive spectrometry （EDS）, and X-ray diffraction （XRD）. Theelectrocatalytic performance and stability of the electrodes for HER were evaluated bylinear sweep voltammetry （LSV） and chronopotentiometry （CP）. Experimental resultsreveal that RuO₂particles are well dispersed on the Ni substrate with tiny cracks, whichincrease the specific surface area of the electrode. At the same time, there is asynergistic effect between the Ni substrate and RuO₂, which not only increase theelectrocatalytic activity toward HER, but also enhance the adhersion strength betweenthe Ni substrate and RuO₂, thus improving the stability of the electrode. To investigatewhether there is a synergistic effect between the Ni substrate and RuO₂, RuO₂wasdeposited on Ti substrate. The result shows that the electrocatalystic activity of Ti/RuO₂ for HER is lower than that of Ni/RuO₂, due to without a synergistic effect between theTi substrate and RuO₂.The Ni-P alloy electrode was prepared by oxalic acid etching and pulseelectrodeposition method. The morphology, structure and composition of theas-prepared electrodes were characterized by SEM and EDS. The catalytic performanceand stability of the electrodes for HER were evaluated by LSV and CP. Experimentalresults show that Ni-P alloy electrode is composed of close-packed particles withsponge-like microstructure, which is helpful for increasing the surface rough of theelectrode, after the Ni substrate etched by oxalic acid. Compared with the electrodeobtained by direct current electrodeposition, Ni-P alloy electrode prepared by pulseelectrodeposition exhibits a lower over-potential for HER. The reason is that pulseelectrodeposition can refine the particles on the electrode and increase specific surfacearea. In addition, Phosphorus plays an important role in promoting the grain refinementand improving the rate of dehydrogenation on electrode. Therefore, Ni-P alloy electrodeexhibits excellent catalytic activity and long-term stability.