(6bv) The OH--Controlled Synthesis of Pt-Ni Nanocatalysts with Different Atomic Distributions for Alkaline Hydrogen Evolution Reaction

Research Interests: My primary research interest is in the area of nanometallic materials and their electrocatalytic properties. Specifically, I work on the system of alkaline hydrogen evolution reaction (HER) and try to prepare platinum-based catalysts by adding some transition metals which could enhance the reaction activity and reduce the cost of the catalysts. I want to explore the relationship between the shape of nanocrystals and their electrocatalytic activities. Moreover, I am interested in the factors which can really influence the alkaline HER activity and intend to use density functional theory method to explore this question.

Teaching Interests: I am interested in teaching knowledge about green chemistry which can solve the global energy crisis and environmental concerns, such as principle and technology of chemical energy saving, synthesis of nanomaterials, technology of fuel cell, electrochemistry and so on.

Abstract: Hydrogen has been regarded as a promising alternative fuel for the future. Nowadays, intense research on pursuing effective platinum-based catalysts for alkaline hydrogen evolution reaction (HER) has been carried out. However, effects of the atomic distribution on the catalytic performance have rarely been investigated. Herein, we demonstrate that a complete alloy-to-hetero phase transformation can be realized under ambient conditions by introducing NaOH in the process of synthesis. Impressively, the Pt-Ni heterostructure with particular atomic distribution exhibits a superior alkaline HER activity, in comparison with the Pt-Ni alloy and commercial Pt-C catalysts. Density functional theory (DFT) calculations reveal the effect of the introduced NaOH to the nanocrystal growth process and explain how the heterostructure with special atomic distribution has been formed. The calculations also demonstrate that the greatly enhanced performance of Pt-Ni heterostructure originates from the superior adsorption ability of H and OH which could reduce the reaction energy barrier. Therefore, we suggest that the alkaline HER performance of Pt-Ni catalysts could be affected by the H and OH binding energies which could be controlled by tuning the atomic distribution.