BN-C异质载体担载Pd的催化氧还原性能

Catalytic oxygen reduction performance of Pd supported on BN-C heterogeneous carrier

氧还原反应(ORR)是质子交换膜燃料电池(PEMFCs)系统重要的阴极反应,研究具有高活性和高稳定性的氧还原催化剂具有重要意义。采用第一性原理计算方法,构建了BN-C异质载体担载Pd金属催化剂理论计算模型,探究了载体对Pd催化氧化还原性能的增强作用,结果表明:相对于BN和碳载体,BN-C异质载体与Pd之间的态密度有着更为明显的轨道杂化,说明二者之间具有强相互作用从而增强催化剂的稳定性;在BN-C的作用下,Pd对O_(2)的吸附及活化得到增强,其吸附能及O—O键长分别为1.064 eV和1.357Å;BN-C进一步促进了O_(2)与Pd之间的电荷转移。由此证明,相对于BN和C载体,BN-C异质结构可进一步增强Pd的催化氧还原性能。

Oxygen reduction reaction(ORR)is an important cathode reaction in proton exchange membrane fuel cells(PEMFCs)system.It is of great significance to study oxygen reduction catalysts with high activity and high stability.The first-principles calculation method was used to construct a theoretical calculation model for Pd metal catalyst supported by BN-C heterogeneous carrier,and investigate the enhancement effect of the carrier on the catalytic redox performance of Pd.The results showed that the density of states between BN-C heterogeneous support and Pd had more obvious orbital hybridization than that between BN and carbon support,which indicated that there was a strong interaction between them to enhance the stability of the catalyst.The adsorption and activation of O_(2) by Pd are enhanced under the action of BN-C,with the adsorption energy and O-O bond length being 1.064 eV and 1.357Å,respectively.At the same time,BN-C further promoted the charge transfer between O_(2) and Pd.It is demonstrated that the BN-C heterostructure can further enhance the catalytic oxygen reduction performance of Pd compared with BN and C supports.