Combinatorial High-throughput Screening Catalysts For Hydrogen Evolution Reaction

The rapid development of the world economy has driven the global demand for energy to increase exponentially,and the extensive use of fossil energy has caused increasingly serious environmental problems.Hydrogen energy is a clean and pollution-free secondary energy source with rich application scenarios.Hydrogen production by electrolysis of water has the characteristics of green pollution-free and high raw material utilization rate.The key to developing hydrogen production by water splitting lies in the development of hydrogen evolution catalytic materials.Multi-component alloys are expected to become excellent hydrogen evolution catalytic materials due to the synergy between different elements.There are a large number of composition combinations between different elements,so it is difficult to quickly screen out alloy composition systems with excellent performance in calculations and experiments.The combined high-throughput method has been shown to significantly speed up material discovery and optimization,but so far there is no effective high-throughput method to screen hydrogen evolution catalytic materials.First,we developed a high-throughput method.The combined high-throughput method can quickly realize the parallel preparation of a series of samples and the high-throughput characterization of the catalytic hydrogen evolution performance.Through this method,it is possible to screen out new hydrogen evolution catalytic materials with development potential in a short time,and greatly improve the development speed and efficiency of new materials.This method successfully screened out materials with high catalytic activity from the Ni-Co-Ti ternary system and carried out repeated experiments to verify that the high-throughput parallel bubble screening has sufficient reliability.The Ni_56.5Co₃₅Ti_8.5 and Ni_57.5Co₃₅Ti_7.5samples selected by this method have better catalytic performance for hydrogen evolution reaction.Their over potentials at the current density of 10 m A cm^-2 are 235m V and 220 m V,which are significantly better than Ni₄₆Co_35.5Ti_18.5（η=300 m V）and Ni₅₀Co₃₇Ti₁₃（η=285 m V）samples;their Tafel slopes are 82 m V dec^-1 and 83 m V dec^-1,which are also better than Ni₄₆Co_35.5Ti_18.5(88 m V dec^-1)and Ni₅₀Co₃₇Ti₁₃(91m V dec^-1).This method has a wide range of applicability,not only for ternary alloys,but also for rapid screening of binary to more than ten-element alloys through the selection of target materials.This method is important for improving the development speed and efficiency of hydrogen evolution catalytic materials.Then,we optimized the screening of components with high catalytic activity through the method of micro-doping Pt and etching,with the purpose of further improving its catalytic hydrogen evolution performance and commercial application potential.The overpotential at a current density of 10 m A cm^-2 decreased from 220m V to 197 m V after a trace amount of Pt was doped.The etching scheme is used to prepare the nanostructures.After etching,the overpotential of the sample is reduced at a current density of 10 m A cm^-2,and the optimization effect of etching for 15 h is the most obvious.Compared with the original sample,the overpotential of Ni_56.5Co₃₅Ti_8.5 etched for 15 h at a current density of 10 m A cm^-2 decreased from 235m V to 167 m V.The overpotential of the Ni₄₆Co_35.5Ti_18.5 sample is reduced from 300m V to 167 m V,which is a decrease of 133 m V.In short,in the research and development model based on the Materials Genome Initiative,a high-throughput preparation and characterization scheme for rapid screening of hydrogen evolution catalytic materials has been developed for the first time.Using this scheme,the Ni-Co-Ti ternary system was used as an example to screen and optimize the performance of high-throughput catalytic hydrogen evolution.This work has important enlightenment and guiding significance for the material genome project and the rapid development of electrolytic water catalysis materials.