Lu Siqi, Zhuang Zhongbin
State Key Lab of Organic-Inorganic Composites and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology , Beijing 100029, China.
J Am Chem Soc. 2017 Apr 12;139(14):5156-5163. doi: 10.1021/jacs.7b00765. Epub 2017 Mar 29.
Catalysts for hydrogen oxidation reaction (HOR) in alkaline electrolyte are important for anion exchange membrane fuel cells. Understanding the role of OH during the HOR catalytic process in alkaline electrolyte is essential to design highly active HOR catalysts. Here, we attempt to isolate the influence of OH by using surface-controlled Pt based nanoparticles as the model catalysts. With a comparison of the HOR activity between PtNi nanoparticles and acid washed PtNi nanoparticles, which have almost the same hydrogen binding energies but much different OH binding energies, it was found that the HOR activity in alkaline electrolyte is not mainly controlled by the OH adsorption. Therefore, a bifunctional catalyst promoting OH adsorption may not useful for HOR in alkaline electrolyte. Tuning the hydrogen binding energy was found to be an efficient way to enhance the HOR activity, and making Pt base alloy is a reasonable way to tune the hydrogen binding energies.
碱性电解质中氢氧化反应（HOR）的催化剂对于阴离子交换膜燃料电池至关重要。了解OH在碱性电解质中HOR催化过程中的作用对于设计高活性HOR催化剂至关重要。在此，我们尝试通过使用表面可控的Pt基纳米颗粒作为模型催化剂来分离OH的影响。通过比较具有几乎相同氢结合能但OH结合能差异很大的PtNi纳米颗粒和酸洗PtNi纳米颗粒之间的HOR活性，发现碱性电解质中的HOR活性并非主要受OH吸附控制。因此，促进OH吸附的双功能催化剂可能对碱性电解质中的HOR无用。发现调节氢结合能是提高HOR活性的有效方法，而制备Pt基合金是调节氢结合能的合理方法。
