Research On Fabrication And Electrocatalytic Performance Of Metal @C Nanocomposite

Direct methanol fuel cell(DMFC)is a kind of proton exchange membrane fuel cells.It has been attracting considerable attention in clean energy technology due to their high energy density,high efficiency and cleanliness,easy storage and transportation of liquid methanol at ambient conditions.Development of high-performance catalysts is critical for the direct methanol fuel cell,while most of them could not be improved to the industrial standard because of the cost and the catalytic activity.Therefore,to explore high-performance catalysts is the focus in recent years.We utilized an arc-discharge approach with an ultrafast cooling system to synthesize the core@shell structural Au@C nanocomposite,comprising 3?5 nm gold clusters confined within high-defective graphitic layers.Such a construction not only improves the conductivity for accelerating the penetration of ions and electrons during the electro-catalytic process of methanol molecules,but also suppresses the chemical/thermal coarsening of gold clusters.More importantly,the atomic-scale Au/C interfaces contribute to a synergistic effect for enhancing the activity over other gold-based catalysts in the electro-oxidation methanol reaction.This work highlights the role of heterogeneous interfaces on the catalytic efficiency of metal catalysts and rationalizes optimization in catalyst engineering.Additionally,tungsten carbide(WC)has been proven Pt-like features and presents promising potentials to substitute noble metal-based electrocatalysts.We synthesized W-C catalysts with a mean diameter of 1.9±0.9 nm,comprising a high density of single W atoms,sub-nanometer and nanometer WC clusters,which are completely encapsulated in high-defective graphitic layers.The WC@C catalyst exhibits significant electrocatalytic performances in four-electron transfer process for oxygen reduction reaction,simultaneously possessing both high activity and stability.These combined advantages thus result in a competitive potential as a substitute of noble metal-based catalysts,and open up an approach for developing non-noble metal-based catalysts.