Research Progress of PtNi Alloy Catalysts for Oxygen Reduction Reaction

Oxygen reduction reaction(ORR)is the key step in the cathodic catalytic reaction of proton exchange membrane fuel cell(PEMFC). It has been found from trends in oxygen reduction activity(volcano plot)that noble metal Pt has super-high catalytic performance;therefore,the most active commercial catalyst for ORR is still Pt / C so far. On the other hand,driven by the scarce resources and high price of Pt,continuous and numerous research efforts have also been made worldwide,aiming to develop Pt alloy catalysts and non-Pt catalysts. Adding a transition metal to change the d band is the common solution to develop low Pt catalyst. Researchers found that PtNi / C catalyst has an ORR activity far exceeding the commercial Pt / C catalyst. However,during operation the transition metal Ni atoms are prone to leach in the acidic condition,collapse the near-surface structure,lose the active facets,depress the ORR activity,and thus result in low stability for practical application. Currently the corresponding research is mainly focused on regulating catalyst crystal plane,surface strain and structure. By changing these factors,the electrochemical activity and durability of the catalyst can be improved. In particular,the octahedral shape has made the most remarkable progress on the surface of Pt3 Ni(111)alloy,and the nanometer PtNi alloy octahedron sealed by (111)surface has become a very promising ORR bimetallic electrocatalyst. And besides,changing the support and element modification could also improve the ORR catalytic performance. This review addresses the current development of Pt-Ni based catalysts for oxygen reduction reaction. The main aspects entailed include:adjusting the exposed facet by morphology control,elements doping and modification,optimizing the support or developing new supports. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.