CoO/NPC@SnO2 bifunctional catalyst obtained by employing metal organic frame and preparation method thereof

Abstract

The invention discloses a preparation method of a CoO / NPC@SnO2 bifunctional catalyst obtained by employing a metal organic frame. The method comprises the steps of: (1) preparing MoFs; (2) performingheat treatment of the MOF3 obtained in the step (1) to obtain a catalyst precursor (Co / NPC) of the nitrogen-doped porous carbon-coated cobalt with a rhombic dodecahedron structure; (3) stirring the precursor obtained in the step (2) and a tin source, and performing reduction by employing a reducing agent to obtain a Co / NPC@Sn catalyst precursor with a core-shell structure; (4) performing further heat treatment of the precursor obtained in the step (3) to prepare a direct methanol fuel cell cathode catalyst with excellent performances; and (5) taking the composite catalyst prepared in the step(4) as a carrier, and performing depositing and dispersing uniformly Pt nano particles to prepare a direct methanol fuel cell cathode catalyst with high catalytic activity. The method is simple in operation, the catalyst is controllable in morphology and high in catalytic efficiency, and method has good application prospects.

Description

technical field [0001] The invention relates to the fields of electrocatalysis and fuel cells, specifically a rhombohedral dodecahedral core-shell structure CoO / NPC@SnO obtained from metal-organic frameworks (MOFs) 2 Composite nanocatalyst is used as anode and cathode bifunctional catalyst for direct methanol fuel cells (DMFCs) and its preparation method. Background technique [0002] In the past decades, direct methanol fuel cells (DMFCs) have been considered as promising energy sources due to their high efficiency, safe storage, low operating temperature and environmental friendliness, and have been applied in portable electronic devices and electric vehicles; The efficiency of DMFCs mainly depends on two important reactions: the methanol oxidation reaction (MOR) at the anode and the oxygen reduction reaction (ORR) at the cathode; therefore, it is necessary to develop efficient catalysts that can promote these two reactions; so far, Pt-based catalysts are the most commonl...

AI Technical Summary

Problems solved by technology

[0002] In the past decades, direct methanol fuel cells (DMFCs) have been considered as promising energy sources due to their high efficiency, safe storage, low operating temperature and environmental friendliness, and have been applied in portable electronic devices and electric vehicles; The efficiency of DMFCs mainly depends on two important reactions: the methanol oxidation reaction (MOR) at the anode and the oxygen reduction reaction (ORR) at the cathode; therefore, it is necessary to develop efficient catalysts that can promote these two reactions; so far, Pt-based catalysts are the most commonly used catalysts in DMFCs because they have good catalytic activity for both the MOR of the anode and the ORR of the cathode; in particular, Pt-based catalysts exhibit irreplaceable catalytic activity for MOR; however, the active sites on Pt are easily Catalyst poisoning caused by the adsorption of intermediate product CO, which leads to poor durability of Pt-based catalysts in the MOR process; moreover, Pt is a precious metal resource, and the high cost and scarcity of Pt-based catalysts are the main obstacles to the commercialization of DMFCs; therefore, it is urgent It is necessary to explore an efficient and relatively cheap MOR catalyst support, which can avoid carbon monoxide (CO) poisoning of Pt active sites, and can reduce the Pt loading of the catalyst, and at the same time, has a good catalytic effect; the choice of cathode catalyst Also greatly affects the performance and cost of DMFCs; generally, the ORR of the cathode is kinetically slow, which requires a catalyst to accelerate the reaction; Pt-based catalysts with high activity are generally considered to be the preferred cathode catalysts; however, due to the The permeation of methanol in the chamber makes the catalytic activity and efficiency of Pt-based catalysts significantly reduced, which has attracted widespread attention; therefore, the easy poisoning and high cost of Pt-based catalysts have led to the development of a series of high-activity, usable (low-cost) and durable Sexual catalyst support becomes more urgent

Images