Application Of Single-atom Catalysts Prepared Based On Strong Metal Support Interaction In Hydrogen Evolution Reaction

Nowadays,the excessive consumption of a large number of fossil fuels and the greenhouse gases(such as carbon dioxide)produced by its combustion have caused serious damage to the global ecosystem.Therefore,in order to seek sustainable development,a basic consensus has been formed to implement the "carbon neutralization"strategy on a global scale.Hydrogen is regarded as an ideal carrier of clean energy because of its high energy density and zero carbon emission.Compared with the traditional steam reforming in industry,electrolytic water solitting is considered to be one of the most promising hydrogen production technologies.It can be combined with renewable energy such as solar energy,wind energy and tidal energy to realize the storage and utilization of excess energy and finally achieve the purpose of energy redistribution.Electrocatalyst plays a key role in hydrogen production from electrolytic water splitting.As a new type of catalyst,single-atom catalyst has unique electronic structure and can be used as an ideal model for electrolytic water splitting electrocatalyst.In this paper,two excellent single-atom catalysts were synthesized with CoPO as the carrier.Combined with synchrotron radiation X-ray absorption spectroscopy and high-resolution scanning transmission electron microscopy,the coordination environment and distribution of catalytic active centers were observed from the atomic scale,and the effect of strong metal support interaction on hydrogen evolution performance was revealed.The main contents are as follows:1.Study on iridium single-atom hydrogen evolution catalyst.A new type of iridium based single-atom catalyst was prepared on foam nickel by wet chemical method IrSACoPO.By means of spherical aberration electron microscopy and synchrotron radiation X ray absorption spectroscopy,Ir was proven to be successfully anchored on the CoP/Co(PO3)2 heterogeneous interface in atomic form.It is proved by density functional theory calculation the anchoring of Ir realizes the strong metal-support interaction and promotes the charge transfer,then promotes the catalytic activity.The electrochemical performance test shows that under alkaline conditions,it only needs 33 mV overpotential achieve the current density of 10 mA cm-2.Furthermore,IrSA-CoPO delivers a TOF as high as 5.89 s-1 at the overpotential of 100 mV,demonstrating its high intrinsic activity.2.Plasma assisted modification of ruthenium based single-atom catalysts and its hydrogen evolution performance A novel ruthenium single-atom catalyst P_Ru-CoPO was synthesized by plasma etching the surface of the support.The existence of ruthenium in atomic dispersion was revealed by spherical aberration electron microscope.Xray photoelectron spectroscopy revealed that strong metal-support interaction occurs between Ru and CoPO after plasma etching.This strong metal-support interaction promotes the charge transfer between metal active sites and reactants,and realizes efficient electrocatalytic hydrogen evolution activity.Electrochemical tests show that P_RuCoPO has outstanding activity for hydrogen evolution reaction in alkaline condition,which only 18 mV overpotential is required when the hydrogen production current density is 10 mA cm-2.This performance is even better than the Pt catalyst.