Electrocatalytic water oxidation homogeneous diatomic catalyst, and preparation method therefor and use thereof

Abstract

The present invention relates to the technical fields of electrocatalysis and chemical industry, and specifically relates to an electrocatalytic water oxidation homogeneous diatomic catalyst, and a preparation method therefor and a use thereof. The catalyst comprises a carrier and a homogeneous diatomic active site having an adjacency structure, and the active site is anchored in the carrier; the carrier is at least one of an oxide, a hydroxide and an oxyhydroxide of a 3d transition-metal; a coordination structure is formed between the double atoms and the carrier. The intrinsic activity of a diatomic dispersed catalytic material prepared by the method in an electrocatalytic water oxidation reaction is equivalent to that of the existing natural photosynthetic system II having the highest efficiency, at the same time, the water oxidation initial potential is merely 170 mV, and the stability is kept for 650 h under a current density of 20 A cm −2 ; and the preparation method is simple and has low cost.

1 . A homogeneous diatomic catalyst, comprising a carrier and a homogeneous diatomic active site having an adjacency structure, and the active site is anchored in the carrier, wherein the carrier is at least one of oxide, hydroxide, and oxyhydroxide of 3d transition-metal, and a coordination structure is formed between the diatomics and the carrier. 
     
     
         2 . The homogeneous diatomic catalyst according to  claim 1 , wherein the 3d transition-metal is at least one of Ti, V, Mn, Fe, Co, Ni, Cu and Zn; and atoms of the homogeneous diatomics are identical metal element, and in the catalyst, the atomic specie of the diatomics is at least one of Ir, Ru, Ni, Fe, Co and Mn. 
     
     
         3 . The homogeneous diatomic catalyst according to  claim 1 , wherein a interatomic distance of the homogeneous diatomics is 1.5 to 3.5 Å. 
     
     
         4 . The homogeneous diatomic catalyst according to  claim 1 , wherein a metal loading of the homogeneous diatomics is 0.1-5.0 wt. %. 
     
     
         5 . The homogeneous diatomic catalyst according to  claim 1 , wherein a coordination number of the homogeneous diatomics is 3.0-6.0, and an existing form of the homogeneous diatomics is ionic state with a valence state ranging from +2 to +7. 
     
     
         6 . A method for preparing the homogeneous diatomic catalyst according to  claim 1 , comprising the following steps of:
 S1) dispersing the carrier in a solvent I to prepare a suspension A;   S2) dissolving a metal dimer precursor in a solvent II to obtain a solution, slowly adding the solution into the suspension A with fully mixing to obtain a mixture, and then removing the solvent in the mixture by means of at least one of filtration, centrifugation, freeze-drying, rotary evaporation, and heating evaporation to obtain a product B; and   S3) calcining the product B after grinding, and obtain the catalyst.   
     
     
         7 . A method according to  claim 6 , wherein in step S1, a mass ratio of the carrier and the solvent I is 1:10-1:10000; and
 the solvent I is at least one of water, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, methanol, ethanol, isopropanol, cyclohexanone, methylphenyl cyclohexanone, acetone, methyl butanone, methyl isobutyl ketone, acetonitrile, and pyridine.   
     
     
         8 . The method according to  claim 6 , wherein in step S2, the metal dimer precursor has a structural formula as follows: 
       
         
           
           
               
               
           
         
         wherein, Mis a metal comprising at least one of Ir, Ru, Ni, Fe, Co and Mn, R is a coordination atom comprising any one of O, Cl, C, N, P and S, a valence state of the metal in the metal dimer precursor is 0 to +5, the distance between the metal atoms is 1.5 to 3.5 Å, and a coordination number of the metal atoms is 2 to 7; 
         the solvent II is at least one of water, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, methanol, ethanol, isopropanol, cyclohexanone, tolylcyclohexanone, acetone, methylbutanone, methyl isopropyl ketone, acetonitrile, and pyridine; 
         a mass ratio of the metal to the carrier in the metal dimer precursor is 1:20 to 1:1000; and 
         a mass ratio of the metal dimer precursor to the solvent II is 1:10 to 1:1000. 
       
     
     
         9 . The method according to  claim 6 , wherein in step S3, a calcination atmosphere is at least one of air, oxygen, nitrogen and argon, a calcination temperature is 100-1200° C., and a calcination time is 10 min-10 h. 
     
     
         10 . A use of the homogeneous diatomic catalyst according to  claim 1  in (photocatalysed) water electrolysis for hydrogen production, (photocatalysed) electrocatalytic carbon dioxide reduction, and (photocatalysed) electrocatalytic nitrogen reduction.