Efficient Synthesis of Bimetallic Pt₃Zn Alloy Nanocrystals with Different Shapes and their Enhanced Electrocatalytic Activity

Abstract

Highly uniform dispersed bimetallic Pt 3 Zn alloy nanocrystals (NCs) with unique geometries are obtained via a facile one-pot synthesis process by regulating different reductants. To investigate the morphology and composition of the prepared catalysts, the transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy are utilized. Electrochemical measurements reveal that the Pt 3 Zn NCs significantly exhibited larger electrochemically active surface areas and excellent catalytic activity towards electro-oxidation of meth-anol and ethanol in comparison to the commercial Pt/C. The optimized Pt 3 Zn (AA) NCs exhibit excellent mass activities in both methanol oxidation reaction (1251.4 mA mg Pt À 1 ) and ethanol oxidation reaction (975.7 mA mg Pt À 1 ) in acidic media, which are respectively 4.28 times and 3.02 times higher than those of commercial Pt/C. Moreover, the Pt 3 Zn NCs show a higher stability and better resistance to the CO ads poisoning. The activity enhancements are attributed to electronic effects and a bifunctional mechanism.[a] X.

Surface oxygen-mediated ultrathin PtRuM (Ni, Fe, and Co) nanowires boosting methanol oxidation reaction

“…catalysts have been widely studied. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Among them, Pt-Ru catalyst is the most effective and has better CO antipoisoning performance for MOR in acidic medium. [6] [23][24] Based on the "bifunctional mechanism", the addition of Ru can cause two effects: firstly, the electrons can transfer from Ru to Pt, weakening the interaction between Pt and CO. Secondly, it may increase oxygen species coverage on the catalyst surface at lower potential.…”

Controlled Preparation and Anti‐Sulfate Electrocatalysis of Self‐Assembled Multidimensional PtZn Quasi‐Cubic Nanodendrites

“…[ 5 ] This kind of change in electronic structure leads to increase in electronic coupling between PtZn and carbon support, [ 7 ] which weakens the adsorption energy of the reaction intermediate, thereby enhancing the oxygen reduction activity. [ 46,47 ] Furthermore, Zn 2p peaks disclosed the coexistence of Zn 0 and Zn 2+ in both the PtZn ND and the PtZn FL, Figure 4c, which was evidenced by the Zn 2p 3/2 peak centered at 1022.5 eV consisting of the contributions of both Zn 0 2p 3/2 and Zn 2+ 2p 3/2 that located at 1021.5 and 1022.6 eV, respectively. And the Zn 2p 1/2 peak at 1045.4 eV divided into Zn 0 2p 1/2 and Zn 2+ 2p 1/2 , located at 1044.6 and 1045.5 eV.…”

“…[ 43 ] Thus, it is a feasible way to enhance the ORR activity and stability of Pt‐based nanocatalysts through adding zinc to form Pt‐based alloy. [ 44–47 ] However, compared to others 3d transition metals, only a few studies focused on PtZn nanocatalysts and their applications in ORR due likely to the quite negative redox potential of Zn 2+ /Zn (−0.76 V vs SHE). [ 45–51 ] Furthermore, most of the reported PtZn nanocatalysts consisted largely of spheres and cubes which are dominated by low‐index facets and easy to be poisoned or have inferior ORR activity.…”

“…[ 44–47 ] However, compared to others 3d transition metals, only a few studies focused on PtZn nanocatalysts and their applications in ORR due likely to the quite negative redox potential of Zn 2+ /Zn (−0.76 V vs SHE). [ 45–51 ] Furthermore, most of the reported PtZn nanocatalysts consisted largely of spheres and cubes which are dominated by low‐index facets and easy to be poisoned or have inferior ORR activity. [ 45–51 ] For the purpose of further improving the ORR performance of PtZn nanocatalysts, in particular the anti‐sulfate poisoning ability, it is very important and meaningful to investigate the controlled growth of PtZn bimetallic nanocrystals with high‐index facets and the high atom utilization.…”