Electroless Deposition Of Mental Nanoparticles On Porous Carbons For Hydrogen Evolution Reaction

The rapid construction of stable and versatile catalysts for hydrogen evolution reaction（HER）over a wide p H range is of great interest.Herein,a one-step rapid electroless deposition strategy was employed to prepare metal nanoparticles-supported porous carbon catalysts.The main driving force for electroless deposition is the reduction potential difference between the substrate porous carbon（NPSC）and various metal ions.The prepared catalysts were tested for HER catalysis in acidic and basic media and the catalytic active sites were explored.The main contents and innovations are:1.The doping of N,P and S elements in the crosslinked polyphosphazene PSTA was realized by mild polymerization.The PSTA has obvious spherical structure with a size of about 500 nm.Porous carbon NPSC was obtained by carbonization of PSTA at 1000℃.The removal of N,P and S elements during carbonization results in abundant pore structure（average pore size 1.92 nm）,specific surface area(1312.77 m²g^-1)and appropriate surface potential for NPSC.After carbonization,NPSC failed to maintain spherical structure,and its morphology was like a broken block of cheese.2.The Ru Pd/NPSC catalyst was prepared by electroless deposition method,which improved the acid catalytic HER ability of Ru/NPSC catalyst.The uniform deposition of Ru and Pd in??the form of nanoparticles was confirmed by TEM and XPS.UPS test showed that the potential of NPSC increased after deposition（from-0.07 V vs.SHE to+0.25 V vs.SHE）,indicating that the driving force of electroless deposition was the potential difference between NPSC and Ru³⁺/Ru⁰,Pd²⁺/Pd⁰.The catalytic capacity of HER was tested in alkaline and acidic media,and the overpotential was 15 m V and 67 m V at the current density of 10 m A cm^-2,respectively,and both showed better stability than Pt/C.By comparing Ru/NPSC and Pd/NPSC,it is confirmed that the catalytic activity of Ru Pd/NPSC in alkaline and acidic conditions is derived from Ru and Pd nanoparticles,respectively,indicating that the electroless deposition process can integrate multiple metal catalytic capabilities.3.Ru Ni/NPSC and Rh Pd/NPSC catalysts were prepared by electroless deposition methods.Ru Ni/NPSC was prepared by using excess Ni source.Through ICP-MS and XPS tests,it was found that the Ni element on NPSC was only 0.47 wt%and still existed in the form of Ni²⁺.The above results show that the electroless deposition process from Ni²⁺to Ni⁰hardly occurs,which is mainly due to the small potential difference between Ni²⁺/Ni⁰and NPSC.Rh Pd/NPSC catalyst showed almost the same HER catalytic ability as Pt/C in acidic(38 m V at 10 m A cm^-2)and alkaline medium(40 m V at 10 m A cm^-2),and its performance was significantly higher than Rh/NPSC and Pd/NPSC.The results show that the mutual doping between metals can be realized by electroless deposition methods,so as to realize the synergistic catalysis of HER process.