Low-temperature Oxidation Of CO On Au-M@C Nanospheres With Resistance To Acid

Porous carbon spheres have attracted widely attention due to their superior properties,such as high stability of thermodynamic and chemical properties,high mechanical strength,high conductivity and good biocompatibility,and controllable pore structure and high specific surface area.In addition,ultrasmall porous carbon nanospheres(10-100 nm)also have the advantages of shorter diffusion channels and less travelling blockage.All these make the porous carbon nanospheres have potential applications in fields of catalysts and catalyst supports.The in situ synthesis of porous carbon nanospheres containing active centers is becoming more and more attractive.Methanol fuel cell will produce toxic CO.CO can poison the electrode Pt,which reduces the power output.Methanol fuel cell with H+ needs a catalyst with acid resistance to catalyze CO oxidation.Nobel metals perform high catalytic activity to CO oxidation.So Au-M@C with acid resistance were used in this paper.In this paper,the main content is the synthesis of carbon nanospheres and in situ synthesis of Au-M@C nanospheres.The catalytic performance of Au-M@C nanospheres for CO oxidation was carried out.We synthesized ultrasmall carbon nanospheres with an average diameter of 20 nm by a facile and mild reverse microemulsion-hydrothermal method.Resorcinol and formaldehyde were used as the carbon precursor.Au@C composite materials were synthesized successfully by the same reverse microemulsion-hydrothermal method as well.But the Au particles tended to aggregation to larger particles due to the absence of affinity of Au and carbon carrier.This will decrease the activity of the Au@C catalyst.We also synthesized N doped carbon nanospheres by reverse microemulsionhydrothermal method.4-Aminophenol and formaldehyde were used as the carbon precursor.N containing species can enhance the affinity of Au onto carbon supports.Au@C composite materials with functional amino were synthesized successfully by the same reverse microemulsion-hydrothermal method mentioned above and the Au particles had an average diameter of 2.0 nm.We also synthesized Au-M@C composite materials(M = Pd,Pt,Ag,Cu,Ni),and studied the catalytic oxidation of CO and resistance to acid by Au-M@C materials.The results showed that the acid-proof Au-Pd@C catalyst performed high catalytic activity of CO oxidation,and the CO conversion rate reached 100 % at the temperature of 150 ?.