Intermetallic compound catalyst and method for preparing intermetallic compound catalyst by using bimetallic complex

Abstract

The invention provides a method for preparing an intermetallic compound catalyst by using a bimetallic complex. The method comprises the following steps: S1) mixing thioacetic acid, sodium bicarbonate, potassium chloroplatinite and a transition metal salt in an aqueous solution to obtain bimetallic complex molecules separated out in a precipitate form; s2) carrying out moisture removal treatment on the bimetallic complex molecules; s3) mixing the dewatered bimetallic complex molecules with carbon black in a mixed solvent of tert-butyl alcohol and water, and freeze-drying to obtain a mixture of the bimetallic complex molecules and the carbon black; and S4) calcining the mixture in a reducing atmosphere to obtain the intermetallic compound catalyst. The intermetallic compound catalyst prepared by using a freeze drying method can form high-loading platinum load at a low annealing temperature, the atomic ratio of platinum to transition metal is clear 1: 1, the composition is controllable, the size distribution is uniform, and the atomic alloying degree is high. The method is simple to operate, has universality and is suitable for industrial production.

Description

technical field [0001] The invention relates to the technical field of nanometer materials, in particular to an intermetallic compound catalyst and a method for preparing the intermetallic compound catalyst by using a double metal complex. Background technique [0002] In the past three decades, proton exchange membrane fuel cells have developed rapidly as a power source for electric vehicles, and understanding the basic principles of related electrocatalytic processes can provide us with ideas for designing efficient and stable proton exchange membrane fuel cell catalysts. At present, Pt is still a precious metal single substance catalyst that is difficult to replace in proton exchange membrane fuel cell catalysts. In the process of designing high-efficiency platinum-based proton exchange membrane fuel cells, the loading of high-load platinum on the cathode catalyst is very important, which is Since the extreme loss of power density is observed in proton exchange membrane f...

AI Technical Summary

Problems solved by technology

Liquid-phase synthesis is only suitable for some alloy systems with low boiling points, and additional surfactants and reducing agents need to be added during the synthesis, the operation is complicated and not suitable for large-scale preparation; while in the general thermal annealing method, the impregnation method is first used to combine two different The metal precursors are impregnated directly on the carbon support. Although the method is simple, it lacks the control of the uniformity of the size and composition of the ordered Pt-based alloy nanoparticles.

Especially when the metal loading increases, there is a strong affinity between metal atoms, and the particles are easy to agglomerate, which eventually leads to a decrease in the electrochemically active surface area of ​​the catalyst.

Therefore, there are few reports on the synthesis of ordered platinum-based intermetallic compound fuel cell catalysts with acceptable size, controllable composition and high noble metal platinum loading.

Images